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
If we assume that the standard RPG classes are present in Mass Effect, the immediate correlations would be Soldier/Warrior, Adept/Mage and Engineer/Rogue. The sentinel class can be described as a hybrid between a "glass cannon" mage and a "stealth class" rogue. The description, however, is not be entirely valid for the Sentinel as, although gameplay does focus on disabling enemy defenses with Warp and Overload, and crowd controlling on the field via Cryo Blast and Throw, this class can also soak up a good amount of damage through Tech Armor. The main two weaknesses that plague the sentinel are the lack of anti-armor powers and training only in heavy pistols, submachine guns and heavy weapons.

The main difference between ME1 and ME2 Sentinels is the fact that 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 renamed Pull, Stasis has been removed to better facilitate the more action oriented combat, and so on. Another thing worthy of mentioning is the overhauled power targeting system. Now powers such as Warp or Cryo Blast home in on the target when in close range. Some of the biotic powers (such as Pull) 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.

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, and/or nearby ledges.There is also an instant kill posibilty if the target is frozen beforehand, throwing them at an object can shatter them instantly.

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 sentinels' biotic offence, perfectly reflecting the class as a whole, lots of aplications but with limited power.Firstly,as mentioned before, it stops health generation, making it very useful on krogan and vorcha enemies, it is potent agains 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 or pull or even slam with a very exact timing, it will detonate causing damage and knocking back nearby enemies next to the target.

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 reloading. On the odd ocasion 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.

Overload
The other defence 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.Unlike warp against armor, overload against shields is very efficient, disabling defences on no more then 2 or 3 applications.

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.The only crowd control ability available to this class, it also presents the ability to curve over cover, allowing a couple of safe shots to be fired without fear of retaliation.Frozen enemies are also more susceptible to direct damage and can shatter when their health is low enough.

Defender
As the class ability of the sentinel, it mostly rounds up your statistics by reducing the cooldown time on your abilities, optionally giving them more power, increases your health and gives a negotiation bonus by boosting your Paragon/Renegade points.

Bonus Power
As a Sentinel, you'll be constantly spamming all your other powers, so a taking a passive power as bonus is recommended. As Overload makes short work of shields, and Warp eats through barriers and its somewhat effective against armor, an ammo power effective against armor (like Armor Piercing Ammo) will complement your Sentinel nicely (though for the most part you won't need more than the initial point in this power).

As an alternative, Inferno Grenade from Zaeed Massani can be a useful anti-armor power. And it is easily acquired as Zaeed loyalty mission is available from the get-go.

Squad Selection
As your Sentinel is effective against all types of enemies, on lower difficulties you're free to choose the companions of your liking. In hardcore / insane, however, Miranda (Warp, Overload, global health and damage bonus) and Mordin (Incinerate) are a very good choice. With them you can easily disable any kind of defenses.

In missions where you know you'll be facing synthetics, you can swap Mordin for Legion (AI Hacking, Widow Sniper Rifle) or Tali (AI Hacking, Energy Drain).