Sentinel Guide (Mass Effect 2)

The Sentinel specializes in a combination of tech and biotic abilities. Though not 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".



Overview
The Sentinel's powers are its main asset, and combat will often focus on attacking enemies with a wide variety of powers. 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 defences: Armor and Biotic Barries with Warp and Shields with Overload. This class is also capable of crowd controlling abilites of Cryo Blast and Throw. It's class ability of Tech Armor can double its shields and provide a shock damage upon destruction. The main weakness of the Sentinel is the lack of weapons training, being able to use only heavy pistols ,submachine guns and heavy weapons, with the option of adding one extra class of weapons during the middle portion of the game. All in all, the Sentinel is a versatile class capable of handling all kinds of situation: CQB or long range, with only notable weakness of facing armored opponents.

For returning players from the first game, there are some major differences that need to be noted regarding powers in general:
 * All powers have been greatly simplified either by condensing more of them into one or getting rid of some completely. As such, Sabotage has been folded into Overload, Barrier has become Tech Armor, Lift was reworked into Pull, Stasis has been removed to better facilitate the more action oriented combat, and so on.
 * The targeting system has been overhauled dramatically. Most biotic powers travel in the direction of your crosshairs and bend their trajectories when close to the intended target, making it possible to hit foes behind cover. Others, such as Overload instantly affect your target without having a travel animation.
 * All cooldowns have been reduced by a large amount, however, a global cooldown (each power, when used, not only activates a cooldown on themselves but also on all other powers as well,equal to the cooldown of the activated power) has been imposed.

Throw
The power uses mass effect fields to hurl targets away, damaging them if they hit an object. It can now be precisely curved around objects and cover to hit its target. Throw really shines when used in combination with pull, in order to reduce the target's mass, launching foes harder against walls or over nearby ledges. There is also an instant kill possibility if the target is frozen beforehand, throwing them at an object can shatter them instantly (Thus combining this power with the Sentinel's Cryo Blast is quite effective). Very similar to the soldier's Concussive Shot, though it cannot affect barriers, but recharges faster, can arc around obstacles, and hits with greater force.

In higher difficulties (Hardcore and Insanity), Throw loses its effectiveness for it is only effective on unprotected enemies. It is still useful, though, to Throw enemies off the edge when they have been stripped of their defences.

At rank 4, it can be evolved in two ways:
 * Heavy Throw: Adds a significant amount of momentum to the power with which enemies get hit.
 * Throw Field: Gives the ability to affect multiple enemies in a small area.

Warp
The power 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 offence, perfectly reflecting the class as a whole, lots of applications but with limited power. Firstly, as mentioned before, it stops health generation, making it very useful on krogan and vorcha enemies. It is potent against armor, although not as much as Incinerate, and biotic barriers. Lastly, but not least, if the target is affected by another biotic ability, such as Reave, Pull or even Slam with precise timing, it will detonate the target, causing damage and knocking back nearby enemies next to the target.

Warp is very useful in higher difficulties, where many enemies are protected with at least a thin layer of armor, and others have both armor and biotic barriers.

At rank 4 it can be evolved in two ways:
 * Heavy Warp: The damage of the ability is hugely increased.
 * Unstable Warp: Increases the blast radius when Warp detonates biotic effects.

Tech Armor
The 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 his companions, having a powerful, unique defensive power really gives the sentinel an edge on higher difficulties. Once activated, the armor remains in use until destroyed, when exiting a combat zone or loading a game (even if you had tech armor active when you saved). On the odd occasion that it does get destroyed, it sends out a pulse of energy, knocking back and damaging nearby enemies within a certain radius of the player. This reactive damage is very useful when facing melee enemies such as husks, or varren; especially as they tend to swarm in large numbers.

In higher difficulties, the Sentinel will be dependent on this power a lot. With skill, a Sentinel may even survive without ever using Medi-Gel to revive fallen henchmen, thanks to this power.

At rank 4 it can be evolved in two ways:
 * Assault Armor : Greatly increases the power,range and damage as well as providing a shield boost when it is brought down.
 * Power Armor : Further increases shields as well as providing a damage bonus to all your powers.

Overload
The other defense-disabling ability available to the sentinel, Overload focuses on shutting down enemy shields, damaging synthetics and, starting with rank 3, overheating weapons. Again, a very useful multi-purpose ability. It can also be used on explosive canisters and flamethrower enemies on the field in order to make them combust and explode.

At rank 4 it can be evolved in two ways:
 * Heavy Overload : Dissimilar to Heavy Warp, it does not make the base ability much more powerful, however, it morphs it into an anti-synthetic version. This class of enemies, will explode upon destruction, damaging the nearby area.


 * Area Overload : Increases the pulse strength to cover a wide area, making it easy to hit multiple targets.

Cryo Blast
When activated, the user's omni-tool 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 can be used to curve over cover to hit the target. While 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. Also, frozen enemies tend to fall behind cover, thus negating your opportunity to finish them off. Throw can be used instead to counter enemies charging at you like krogan, varren or husks (once their defenses are down).

At rank 4 it can be evolved in two ways:
 * Deep Cryo Blast : The potency and duration of the power is enhanced greatly.
 * Full Cryo Blast : Expands spray area to maximize the chances of freezing multiple targets.

Defender
The class ability of the sentinel augments your most important attributes. This power reduces the cooldown timer on your powers, increases your health and gives a negotiation bonus by boosting your Paragon/Renegade points. It can also optionally boost your power damage.

At rank 4 it can be evolved in two ways:
 * Guardian : Provides the greatest bonus to power recharge time and Paragon/Renegade scores.
 * Raider : Gives a damage bonus to all your abilities and a lesser amount of improvement to power recharge time and Paragon/Renegade scores.

Bonus Power
The sentinel can be played in a multitude of different ways. With this much freedom choosing your bonus talent can create a variety of different builds.

Armor Piercing Ammo / Warp Ammo
As a Sentinel, you'll be constantly using your other powers, so taking a passive ammo power such as Armor Piercing Ammo or Warp Ammo will benefit you greatly, especially if you lack a teammate with squad ammo. Armor Piercing Ammo has more damage potential(+70% weapon damage vs. health and armor), while Warp Ammo has more versatility(+50% weapon damage vs. health, armor and barriers). As a Sentinel already has abilities effective against Barriers, it is a matter of personal preference.

Reave
Reave is also a very effective bonus power, as it is effective against barriers, armor, and health, and stuns unprotected organics while giving a bonus to health regen. Although with having access to Warp may Reave seem redundant, a reason you may want to take this power is to free up room for cryo freeze and spend no points in throw.

Geth Shield Boost / Barrier / Fortification
The three bonus shield boosters. Barrier, the Biotic variant, and Geth Shield Booster, the Tech variant, are the recommended options, and are the same except for their Improved variant. Barrier lasts 3x longer(a non-factor for use during combat), while Geth Shield Booster grants a 10% bonus to weapon damage. Their Heavy variants increase the shield boost from 75% to 100%. With proper timing, you can keep restoring your shields to full before enemies can rip both shield buffs off. These talents do have a duration limit unlike Tech Armor, so when you're restoring your shields to full this way, make sure you're activating your bonus talent over Tech Armor. Tech Armor seems to be the only buff that's visually shown when stacking the two armors together.

Weapons
Heavy Pistols, Submachine Guns

Weapon Specialization:
Any of the three bonus weapon training options can be a good choice for a Sentinel, depending on play style. 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, extending 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.

Assault Rifles deal high damage at mid-ranges, and are a good all-around choice for any character, including a Sentinel. If Assault Rifles are chosen, the M-15 Vindicator is probably the best one to carry; while its ammo supply is limited, it is more effective at range than the M-8 Avenger. The Geth Pulse Rifle can also make a good choice as it is extremely effective at stripping shields and barriers.

Finally, Shotguns can synergize with Tech Armor, especially the Assault Armor variant, which makes it easier for a Sentinel to make it into effective shotgun range and can knock down enemies, leaving them open for a point-blank shotgun blast.

Squad Selection
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.

Anti-Armor
Enemy barriers and shields fall quickly to the Sentinel, leaving unprotected/heavily armored enemies to be dealt with by the rest of the team. Squadmates wielding assault rifles (Garrus, Grunt, Legion, or Zaeed) are a good fit for most missions, as is Mordin who can burn through enemy armor with Incinerate.

Squad Ammo
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 most types of defense. 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. Choosing Armor Piercing Ammo from Garrus or Shredder Ammo from Thane for a specific mission might make sense, but the Incendiary Ammo ability that Jacob and Grunt provide is better suited to most situations.

Complementary Abilities
Miranda can be a good choice for any type of mission. Her Warp and Overload powers will assist the Sentinel in quickly overcoming enemy defenses, and her Cerberus Officer ability provides bonuses to the entire squad.

With access to both Warp and Throw, a Sentinel is capable of inflicting biotic combos on enemies if partnered with the proper squadmates. This is easiest to accomplish with Jack, Jacob, or Samara using Pull. It is also possible with Miranda's Slam, but requires more precise timing.

The team's tech specialists, Legion and Tali should not be overlooked. 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.