Sentinel Guide (Mass Effect 3)

Master of nothing but proficient in everything, the Sentinel often ends up the one everyone relies on to draw enemy fire.

Overview
Tech Armor, the Sentinel's unique power, has changed significantly from Mass Effect 2 to Mass Effect 3. Likewise the Sentinel itself plays quite differently.

Tech Armor will no longer automatically detonate after your shields go down. Instead, it must be detonated manually. Furthermore, Tech Armor imposes a significant cool down penalty on your other powers while active. In combination with the new Weight system, all of this results in the Sentinel having two basic build options: one that focuses on weapons, supplementing their defense with Tech Armor, and one that focuses on powers, trading durability for versatility.

If you plan to tank it up with Tech Armor, focus on Fitness as well to make yourself as hard to kill as possible, ignore weight restrictions, and gun everyone down. Even compared to the Soldier this is low-maintenance as you don't need to spam Adrenaline Rush. Due to limits on power points, this build works best with a fresh Mass Effect 3 character, or one who has free run of the Normandy and can reset their powers, rather than one imported from a previous game.

The second way returns to the original Mass Effect  playstyle: eschewing Tech Armor for emphasis on your other powers. You can easily stun and kill light enemies with a maxed-out Overload or by chaining Warp and Throw. The core of this build is versatility: this Sentinel can stand back and use Overload, Warp and (now) a sniper rifle to ruin shields, armor and health in rapid succession. You can even provide one-person biotic combo and tech combos by combining Overload and Cryo Blast, and Warp and Throw.

Tech Armor
As stated above, Tech armor no longer detonates automatically. This allows for players to play more defensively with heavier armor choices or more offensive by increasing the knock-back and damage. The big disadvantage to Tech Armor is that when it is active, powers cool down a lot slower; use light weapon load-outs and other advanced powers to counter.

Throw
Throw is best used as a offensive knock-back tool to dislodge enemies from cover and to set off biotic charges like warp. The Recharge Combo evolution is very useful for Sentinels, as it mitigates the cooldown penalty from Tech Armor. With this evolution and a biotic squadmate, Throw becomes a power that can be used liberally.

Warp
Warp in Mass Effect 3 has been changed in that it does not remove barriers like in Mass Effect 2. It is still potent against armor and it can be set off in a biotic explosion with throw.

Warp's later upgrades can increase the amount of damage the target takes for fifteen seconds or so afterwards. This makes it a great tool against enemies such as Atlas Mechs and Brutes--Warp it and then focus-fire.

Cryo Blast
Cryo Blast is a nice tool in that it slows enemies and might even freeze the target. That said, this power should just be upgraded to Tier 2, as the Sentinel's other powers are a lot more useful.

Overload
Overload has gained a few nice abilities since Mass Effect 2. For starters, it is now the main tool for taking down barriers and shields. Upgraded it gains the ability to jump from multiple enemies, making it a great crowd control weapon.

It also can create a Tech Burst when the same enemy is hit by a Warp.

Lift Grenade
Lift grenades for players transferring from Mass Effect 2 will be relativity useless as Throw can be used unlimited amount of times and can be useful in dislodging enemies. Upgrade to Tier 2 for the 4th grenade and use the points for other powers. This is also not a great upgrade for long-range power-users, since grenades are less dependable than the Sentinel's other target-seeking abilities.

Alternatively, the upgraded grenade can do a significant amount of damage over a large radius, making it a useful offensive power in its own right.

Fitness
Other than the usual improvement in shield, health and melee damage, the Sentinel's Fitness ability is capable of increasing squadmate health and shield by 30% in its 5th upgrade, making them significantly more durable.

Offensive Mastery
Being a passive power, it focuses mainly on increasing power and weapon damage.

Defense Matrix
Coupling a defense-specialized Tech Armor with Defense Matrix is a smart way to survive the more difficult encounters in the game. Defense Matrix also gives you the option of detonating it to restore a portion of your shields, further increasing your survivability.

Marksman
Additional offense is even more wide open since the Sentinel has so much of it to begin with. Marksman is a poor man's Adrenaline Rush, providing increased accuracy but not the "bullet time" slowdown.

Stasis
The one biotic power that the Sentinel lacks is a means of debilitating a target, such as the Adept's Singularity or the Vanguard's Pull. Stasis fills that gap, and gives you another option for generating biotic explosions with Throw or Warp. With the Bubble evolution at rank 6, Stasis becomes effective even on enemies protected by shields or barriers, and can be used to set up traps at bottlenecks.

Reave
This Biotic power works really well as a bonus protection without hindering cooldown, with the right evolutions, the Sentinel can have as much as 80% damage reduction, while still using powers frequently, the only real drawbacks are that it has to be an organic target, and that it only lasts for a small period of time.

Armor-Piercing Ammo
With a protective power, a good grenade power, and enough offensive powers to deal with any protective layers and set-up/detonate 3-out-of-4 power combos, sentinels have it all... except for an ammo power. Armor-Piercing Ammo gives a passive bonus to all weapon damage against health and armor, and all enemies have health or armor. It deals extra damage to all the enemies that are hardest to kill, and makes armor-piercing weapon upgrades unnecessary. Especially on Insanity, it makes a huge difference.

Combat Guide
As a Sentinel, you are a very versatile and can adapt to any situation. You can load up an assault load-out one mission, a CQC load-out the next, then a marksman load-out the mission after.

The main deciding factor is how you load up your Tech Armor. A focus on defense can make you a walking tank and act as a support class, working in the back and managing your squad-mates. Choosing a more offensive Tech Armor will allow you to play as a more aggressive class, with your squadmates supporting you.

The typical weapon loadout for a Sentinel would be an Assault Rifle and a Pistol. For stronger power recharge using a SMG instead of a Assault Rifle. For a stronger weapon load-out, replace the Pistol with a Shotgun or the Talon.

Using an upgraded Mattock or a Raptor will make the Sentinel more of a marksman while keeping the power cool-down tolerable. Adding close range weapons like an SMG or a light shotgun, like the Disciple or the Talon Pistol, will make the Sentinel an all around combat class without too much additional cooldown penalty.

Using a high rate of fire weapon like the Revenant or the Geth Pulse Rifle and an extremely light weapon like a SMG with lightweight materials mod will turn the Sentinel into a squad-support class. Taking the Armor Piercing perk will allow you to take down any enemy with sustained fire.

The extreme combat build invests in Tech Armor, Lift Grenades, defensive bonus powers, passive trees and possibly takes advantage of Throw's ability to not have a cooldown when used to react with another power. With this build, you are free to load up as many weapons as you like, ignoring cooldowns almost entirely besides the odd tech armor explosion or other protective power's cooldowns. The cost is ignoring other powers the class has to offer.

Finally, if you have the From Ashes DLC and its Particle Rifle, all calculations go out the window. The Particle Rifle is an extremely versatile weapon; basically any class can use it as their sole weapon. With nerves of steel and the right point investments, you could potentially build a Sentinel around the Particle Rifle who can switch between play styles at a moment's notice, charging in under Tech Armor and then retreating when necessary or if hardened enemies show up.

Squad Members
The Sentinel is a very versatile class that can combine well with a lot of squadmates. Bringing Liara T'Soni, Kaidan Alenko or Javik will allow you to set up powerful biotic detonations. in particular, the warp/reave detonation combo can deal heavy damage to tough, armored enemies such as the Atlas Mech, Banshee, and Brute. Bringing EDI allows you to set up powerful tech explosions with Overload and Incinerate. Even on Hardcore and Insanity, a fully evolved Overload and Incinerate will very quickly destroy shielded enemies such as the Centurion, Marauder, and deal heavy damage to Phantoms. Tali can provide a Tech Burst option with Energy Drain (followed by Overload or Cryo Blast from Shepard), and render enemies vulnerable to tech and weapon damage with Sabotage.

Bringing Ashley Williams, James Vega, or Garrus Vakarian allows you to have a powerful combatant on your team and gives you access to their grenades and ammo powers.