Sentinel Guide (Mass Effect 2)

Sentinels are unique, bringing both tech and biotic abilities to the battlefield. They are versatile and always equipped to deal with any situation. After overloading an enemy shield, Sentinels have no trouble throwing the opponent with their biotic powers. Additionally when battles become too heated, they can Cryo Freeze an enemy buying the Sentinel precious time eliminate foes or take cover.

Sentinels are also equipped with the most advanced Tech Armor to keeping them safe in hostile situations. If overloaded, the system discharge and stun all enemies within a short distance.

Overview
The Sentinel relies heavily upon tech and biotic powers both for offense and defense. The Sentinel arguably has the most survivability out of any class due to its signature ability, Tech Armor, and its ability to quickly incapacitate dangerous enemies. The Sentinel is the only class capable of disabling all three forms of defenses, armor and biotic barriers with Warp, and shields with Overload. Its class power of tech armor can double its shields and provide shock damage upon destruction. The main weakness of the Sentinel is its lack of weapons training, in that it is able to use only heavy pistols, submachine guns and heavy weapons. All in all, the Sentinel is a versatile class that is capable of handling most situations, ranging from close quarters combat to long range, with its only notable weakness being heavily armored opponents.

Some of the differences between Mass Effect and Mass Effect 2 are that the Sentinel has access to more weapons in the form of heavy weapons and SMGs. There are more powers that can be used more frequently because of the global cool down. The Sentinel is more effective in combat in Mass Effect 2 than in Mass Effect.

Overall, due to their not being as proficient as an Adept or an Engineer in their respective fields, and lacking some advanced weapon training, the Sentinel is considered by most a "jack of all trades, master of none".

Throw
Throw uses mass effect fields to hurl targets away, damaging them if they hit an object. It can also be curved around objects and cover to hit its target. Throw really shines when used in conjunction with Pull, which reduces a target's mass, and thus allows Throw to launch foes against walls or over nearby ledges more forcefully. Throw also has an instant kill possibility: a frozen target thrown at an object may shatter instantly. Combining this power with Cryo Blast makes this quite effective. On higher difficulties, throw loses some of its usefulness as it is only effective against unprotected enemies. It is still useful, however, for throwing enemies off of ledges once they have been stripped of their defenses.

Warp
Unlocks with throw at level 2.

Warp spawns a mass effect field that damages enemy targets and stops health regeneration. Warp can be considered the bread and butter of the Sentinel's biotic offense, perfectly reflecting the class as a whole, lots of applications, but with limited power. First, as mentioned, it stops health regeneration, making it very useful against krogan or vorcha. Second, it is potent against armor, although not to the degree of Incinerate, and against biotic barriers. Lastly, if the target is affected by another biotic ability, such as Pull or Slam, it will detonate the target, cause damage in a radius and knock back enemies near the target. Warp is very useful on higher difficulties, where many enemies are protected by at least a thin layer of armor, and others have both armor and biotic barriers. It is notable that the Warp explosion damages all enemies, even when they are protected. It's also important to remind that the Sentinel's other biotic attack, Throw, is instantaneous and can't be detonated. The biotic bonus powers available to the Sentinel can't be detonated by Shepard alone, either - Reave doesn't trigger the explosion and Slam resumes too quickly for Shepard to use Warp in succession. Therefore, taking an ally with access to Pull or Slam is necessary for exploiting this tactic.

Tech Armor
This power generates an energy armor suit that boosts the user's shields. Considering that most enemies will be much more attracted to the Commander than your squadmates, having a powerful, unique defensive power really gives the Sentinel an edge on higher difficulties. Once activated, the armor remains active until it is destroyed or upon exiting a combat zone or loading a game. On occasions when it does get destroyed, tech armor sends out a pulse of energy, knocking back and damaging nearby enemies within a certain radius of the Commander. This reactive damage is very useful when facing melee enemies such as husks or varren, especially as they tend to swarm in large numbers. It also refills Shepard's shields to maximum upon activation, meaning that it can be used to regenerate your shields once they are downed, granting superior survivability.

Overload
Unlocks with tech armor at level 2.

A very useful multi-purpose ability, it's also the other defense-disabling ability available to the Sentinel. Overload focuses on shutting down enemy shields, damaging synthetics and from rank 3 onwards, overheats weapons. It can also be used on explosive canisters and flame-throwing enemies in order to make them combust and explode. Due to the tendency of enemies crowding close to each other, area Overload is usually the better option on higher difficulties. Against synthetics, the stun effect and the weapon overheating can affect several enemies at once.

Cryo Blast
Unlocks with overload at level 2.

When activated, this powers fires a mass of super-cooled subatomic particles capable of snap-freezing targets within a certain radius. Cryo Blast is the only crowd control ability available to the Sentinel, and it can curve over cover to hit its target. Because the enemy is unable to act during the cryo freeze, safe shots can be fired without fear of retaliation. Frozen enemies are also more susceptible to direct damage and can shatter when their health is low enough. However, any sort of armor, shielding, or barrier prevents the target from being affected, meaning this power loses some of its usefulness on higher difficulty levels. Also, frozen enemies have a tendency to fall behind cover, thus making it difficult to finish them off. Throw can be used instead to counter enemies such as krogan, varren, or husks who may be charging at you.

Defender
The class ability of the Sentinel augments its most important attributes. Defender reduces the cooldown timer on powers, increases Shepard's health and gives a negotiation bonus by boosting Paragon and Renegade points. Both of Defender's evolved forms have advantages depending on play style. Aggressive Sentinel players may prefer Guardian since Shepard can use powers more frequently, while those with a more "artillery" style of play might find Raider to be a better option.

Armor Piercing Ammo
The Sentinel already has many active powers; choosing an ammo power can help boost the Sentinel's damage-dealing capacity without interfering with the cooldown on their other powers. Armor Piercing Ammo adds a moderate damage boost against the health and armor of enemies. Although the Sentinel can strip armor with Warp, Armor Piercing Ammo can act as a useful damage supplement: heavy Armor Piercing Ammo increases weapon damage by 70%. AP ammo will help the Sentinel kill enemies quicker once biotic or tech abilities strip all defenses.

Warp Ammo
Heavy Warp Ammo makes an adequate substitute for Warp for the task of destroying armor and barriers. Certain builds forgo Warp in exchange for maxing out Overload, Throw, Cryo Blast, Defender, Tech Armor, and Warp Ammo in order to maximise their versatility without sacrificing powerful crowd control of maxed out throw or cryo blast on unprotected enemies. Heavy Warp Ammo is a solid choice for Sentinels that will rely on weapons as their main source of damage as Warp Ammo will give a 50 percent damage multiplier to barriers, armor, and all forms of health.

Shredder Ammo
Shredder Ammo will be most useful for a Sentinel more interested in dealing direct damage than using crowd control abilities. Shredder Ammo is the most powerful ammo power (offering a maximum of +80% weapon damage), but only affects the health of organic enemies. This is ideal for a Sentinel who focuses on using Warp and Overload to strip defenses and prefers to gun down enemies rather than freeze them or throw them. As the damage bonus from Shredder Ammo only affects organic enemies, the Sentinel will have to rely on Overload, base weapon damage and crowd control when fighting synthetics.

Reave
Reave is functionally similar to Warp: though it lacks the ability to stop regeneration after its effects wear off, it can stun unprotected organics for a few seconds and provide the Sentinel with health regeneration for that duration (though this regeneration is less useful for Sentinels, who rely primarily on shields). While a Sentinel's access to Warp makes Reave redundant, Reave can substitute for Warp if the Sentinel does not want to spend the necessary points in throw. Choosing this power comes down more to your play style than anything else.

Geth Shield Boost
Geth Shield Boost is the tech defensive power and benefits from the Sentinel's class ability. It is functionally similar to barrier, and only differs in that its improved variant adds 10% weapon damage rather than a longer duration. Though Geth Shield Boost is inferior to Tech Armor, the two can stack for a total protection bonus of up to three times the Sentinel's base shield strength. The long cooldown of Geth Shield Boost can interfere with the Sentinel's other abilities, however, which makes it most useful as a pre-battle buff. Geth Shield Boost can be less useful on higher difficulties, as the increased speed with which enemies can strip shields reduces the time value of the protection that it offers, though many players find the protection it offers invaluable. It should be noted that when activated after Tech Armor, GSB will replenish all your shields including the Tech Armor's shields, providing the armor didn't break. When combined with Tech Armor, GSB can become a permanent layer of shields for its entire duration, and won't "break" off after taking damage as it would for any other class.

Barrier
Barrier is the biotic defensive power and benefits from the Sentinel's class ability. It is functionally similar to Geth Shield Boost, and only differs in that its improved variant adds a longer duration rather than a 10% boost to weapon damage. Though Barrier is inferior to Tech Armor, the two can stack for a total protection bonus of up to three times the Sentinel's base shield strength. The long cooldown of Barrier can interfer with the Sentinel's other abilities, however, which makes it most useful as a pre-battle buff. Barrier can be less useful on higher difficulties, as the increased speed with which enemies can strip shields reduces the time value of the protection that it offers, though many players find the protection it offers invaluable.

Energy Drain
Energy Drain is functionally similar to Overload: while it cannot stun synthetics or overheat weapons, it will give a temporary boost the Sentinel's shield. This is useful for a Sentinel, who relies primarily on shields, and has good synergy with Tech Armor by helping to prevent it from breaking. As it is not strictly better than Overload, choosing this power is primarily a matter of personal preference and playstyle.

Flashbang Grenade
Only available with the Kasumi - Stolen Memory DLC pack.

The Flashbang Grenade combos well with the Sentinel's robust shield-breaking to give an option to shut down packs of enemies preemptively, as it works against enemies protected by armor and barriers/shields. The power is just another one of the ways that a Sentinel can control the battlefield and disable enemies. In addition, because it is a tech type power, it benefits from a Sentinel's class power.

Heavy Pistols
Having only had access to pistols in Mass Effect, these weapons will seem very familiar. Pistols are good weapons at mid to close-range combat, and considering you have access to two different weapons, picking between the two will be more dependent on what other weapons you have, what you will be encountering, and where you are going for you missions and assignments. Normally there are only two pistols, but with the Firepower Pack comes a third, the M-5 Phalanx. The Phalanx is a good weapon that is powerful in close-range, and is accurate in mid-range as well. Any of the three pistols are good and probably switched out based on the mission you are about to undertake.

Submachine Guns
In Mass Effect 2, the SMG adds a huge bonus to the amount of damage that the Sentinel can do, and improves the ability of the Sentinel to provide cover and protect their squadmates. Because you will probably be using SMGs more than your pistols, it is recommended that you try and upgrade the M-4 Shuriken as quickly as possible. This means either doing Tali's recruitment mission, or if you have the Kasumi - Stolen Memory DLC pack, doing Kasumi's loyalty mission, should be a top priority.

M-100 Grenade Launcher
The M-100 Grenade Launcher is the first heavy weapon to be acquired during the Prologue: Awakening mission. The weapon is good against groups of enemies and for knocking back single enemies. The weapon does have a slight arc to it, but it is quick to adapt to. However, the M-100 may not be the best weapon on longer missions because of its limited ammo capacity. Overall the M-100 is a good all around weapon that will fit many situations and will work when no other heavy weapon will fit.

ML-77 Missile Launcher
The ML-77 missile launcher is a good all around weapon that has the added bonus of being able to lock on to enemies and track them. The ML-77 is a good weapon, while lacking the knockdown power of other heavy weapons, the ability to track enemies can outweigh that at times. The ML-77 has a high ammo capacity, which makes it very useful on longer missions and assignments, but because the projectiles don't do as much damage as other heavy weapons, you will use more ammo. Overall, like the M-100, the ML-77 is a good weapon that will also work in just about any situation and if no other heavy weapon will fit.

M-622 Avalanche
The M-622 Avalanche is a good weapon on lower difficulties when enemies don't have protection like armor, shields, and barriers. This weapon also works great against Husks on lower difficulties as well because it can kill them instantly. However on higher difficulties the M-622 loses its effectiveness very quickly. Because all enemies have protection, the chance of freezing is dramatically reduced. The utility of this weapon is also mitigated by the Sentinel's Cryo Blast ability, which is essentially the M-622, just smaller. Overall because of the sentinel's access to the Cryo Blast ability, this weapon has limited usefulness.

M-920 Cain
The M-920 Cain is a powerful weapon to say the least, but unless the weapon has 100% ammo or more, the weapon will not fire. At most you can use the Cain twice during a mission, usually once, so either plan for that, or leave the Cain in the rack. The Cain is powerful, and can destroy enemies, or at least damage them, in a large radius. However since the weapon can only be fired with 100% ammo, either plan to use the weapon only once, or leave it behind.

Collector Particle Beam
Acquired during the mission to Horizon, this can be a good weapon for a Sentinel. While you don't need its ability to rip through the protection that most enemies have, it is still none the less a good weapon if you need long range support. Because the Sentinel has access to powers that can disable shields, like Overload, and deal with armor and barriers, such as Warp, this weapon which can rip right through them does seem to just add to that. However the weapon is great at range and it does have the ammo for a long mission.

M-451 Firestorm
The Firestorm, or flamethrower, is an excellent weapon for the Sentinel who prefers getting up close and personal with their enemies. Because the Sentinel has access to Tech Armor, a powerful defensive ability, getting up close isn't as much of a problem. Also because the Sentinel lacks a close range weapon, the M-451 might be a good option to fill that close-range slot.

M-490 Blackstorm
The Blackstorm is a good weapon if you need some crowd control abilities, and if you aren't going to select any squadmates with them. The singularity produced by the weapon has many uses including throwing enemies into the air, pulling enemies out of cover, and for tying up multiple enemies. Because the Sentinel lacks any form of crowd control abilities, it helps fill in that role. The weapon does have a low ammo capacity, but it is a good weapon for those situations where crowd control is needed.

Arc Projector
The Arc Projector is almost a redundant weapon for the Sentinel because of the Overload ability. The Arc Projector however shines against synthetic enemies like the geth. Even with Overload, this weapon can come in handy against multiple synthetic enemies, or when a lot of enemies you are facing have shields. The Arc Projector has a moderate ammo capacity, which makes it ideal for longer missions, but for the Sentinel, it serves a limited purpose.

Advanced Weapons Training
During the mission aboard the Collector Cruiser, there will be the option of training in the usage of assault rifles, shotguns, or sniper rifles.

Assault Rifles
Assault rifles deal high damage at mid-ranges, and are a good all-around choice for any character, including a Sentinel. Because Sentinels lack any ability to effectively engage at mid to far-range, assault rifles would help the Sentinel provide cover for their squadmates. Any of the two, three if you play on Hardcore or Insanity, or four if you have the Collector's Edition, would be a good addition to the Sentinel's arsenal. A fifth assault rifle is added with the Firepower pack, the M-96 Mattock. The Mattock is a semi-auto rifle, which works like the pistols that you should be familiar with. However it works at longer distances, is more accurate, and does more damage. The Mattock also has a high multiplier against armor, allowing the Sentinel to punch through shields, barriers and armor equally without breaking stride (the Sentinel can use Warp or Overload to take out a primary protection layer, and the Mattock will allow them to attack the armor while the power cools down). Also, the Mattock is accurate at medium to long range, which the Sentinel usually operates at.

Shotguns
Shotguns have good synergy with Tech Armor, especially the assault armor variant, which makes it easier for a Sentinel to approach enemies, knock them down and deliver a deadly point-blank shotgun blast. On higher difficulties, however, this is less advisable: without the Soldier's Adrenaline Rush or the Vanguard's Charge, the Sentinel will be hard pressed when trying to retreat from close quarters combat. Shotguns are still a viable option, however, because the vanilla Sentinel is primarily a mid-range combatant and the shotgun enhances their short range capability. The two DLC shotguns, the M-22 Eviscerator and the Geth Plasma Shotgun, are both recommended: they supplement the Sentinel's mid-range combat style, work well with the Sentinel's robust defenses and do a lot of damage.

Sniper Rifles
Sniper rifles are perhaps the best complement to the sentinel's existing abilities, offering the ability to kill enemies beyond the range at which powers can normally lock on. You can extend that distance while using the sniper zoom, and also providing excellent damage versus armor with the AP sniper rifle upgrade. A Sentinel with a sniper rifle can deal with any enemy, anywhere on the battlefield. On the downside, it might seem a bit awkward when using powers while equipped with a sniper rifle, for the visual is locked into the rifle zoom while the power bolt travels to its target. The Aegis Pack adds the M-29 Incisor, which is good against shields. However with the Sentinel's already healthy access to protection destroying powers, the Incisor may still be a good choice. Still sniper rifles would be a good choice for those Sentinels who wish to keep their distance.

Combat Guide
Combat with a Sentinel is about debuffing enemies and providing fire support to squadmates. The Sentinel has access to powers than can disable every type of enemy defenses and even do further damage to synthetics. The Sentinel also has access to the tech armor power, which helps in close quarters combat by strengthening the Sentinel's shields and providing another layer of defense. Using the Sentinel's powers helps to make enemies easier to take down and to keep them at a distance. The Sentinel’s only crowd control ability, Throw, should be used in the respect of keeping enemies in a distance. It can also be used to throw enemies off a bridge, railings, and well anything else.

Because the Sentinel has access to only three weapon systems, SMGs, Heavy Pistols, and Heavy Weapons, a Sentinel needs to stay a little closer to the action. Using the Tech Armor ability, this is quite easy. The first priority for a Sentinel should be getting an upgrade for their SMG, this means doing either Tali's recruitment mission or Kasumi's loyalty mission. Use the Sentinel's weapons to provide cover and when necessary, attack. The Sentinel may lack a little in weaponry, but makes up for it in the ability to rip through the enemy's defenses. Essentially, the Sentinel must pave the way for their more combat-savvy teammates to take control of the battlefield, staying one step behind in order to support them with protection-stripping powers. On the opposite hand of the spectrum, the Sentinel can act as a well-armored decoy to allow long-range squadmates to pick off enemies while they focus on the Sentinel. Although both tactics are viable, the decoy is more dangerous on higher difficulties.

Squad Members
Sentinels are effective against all types of defense (armor, barrier, and shields). This affords characters of this class a great deal of flexibility in selecting their squadmates. Any combination of team members can be chosen without exposing the squad to any particular weakness, and the most effective teams are usually tailored to fight a specific type of enemy.

However the Sentinel lacks any effective combat skills, so bringing along a character that has access to an assault rifle, or a sniper rifle is a good idea. Mainly the Sentinel needs access to a mid-to-long range shooter for backup. However the person wielding these weapons should be tailored to the specific enemies that you will be facing. This is primarily because the Sentinel is adept at taking down barriers, shields, and armor, so you will need to pick combat squadmates based on their other talents and what they have to offer. Thane, with Warp and a sniper rifle, is a good complement if you can find a spot for him to hang back and snipe. Better still are Garrus, with Concussive Shot and Overload, and both assault rifle and sniper rifle; or Grunt, with researchable 50% health bonus, health regen via Krogan Berserker, and assault rifle. The best might be Zaeed, with a 50% bonus weapon damage, assault rifle and sniper rifle. Legion, to some extent, is also useful for it is the only squad mate capable of using the M-98 Widow after upgrade.

Because Sentinels initially lack any ammo powers of their own; therefore, it's usually a good idea to bring along someone with a squad ammo ability to empower the entire team. Like the Sentinel class itself, Jack's Warp Ammo may be a good choice as it is effective against both Biotic Barriers and Armor. Zaeed's Disruptor Ammo ability is effectively overload as an ammo power, and when evolved into squad ammo it can make the whole team more effective against shields and synthetic enemies. The Disruptor Ammo may be a life-safer when facing enemies like Geth Hunters and Geth Primes. The Shredder Ammo from Thane is effective against unprotected organics, but loses its effectiveness in higher difficulties where nearly every enemy is protected. The Incendiary Ammo power from either Jacob or Grunt is better suited to most situations for it provides bonus against armor, stops health regeneration and sends organics into panicking when their protection has been stripped away. Samara can be useful since the Sentinel's skill set can remove the enemy's protections to allow Samara to hit enemies with Reave, while provided medium range combat abilities and crowd control.

The team's tech specialists, Legion and Tali should not be overlooked either. With their AI Hacking and Combat Drone powers, they can often damage enemies while effectively drawing fire away from the squad. Legion, armed with an assault and sniper rifle, should be selected for his superior weapon damage, while Tali may be preferred against synthetic enemies for her Energy Drain, which effectively mimics Overload. A word of caution: both Tali and Legion are not strong in the health department and may fall quickly if the enemies focus assault on them.