Best bonus power for Sentinel for ME2 and ME3

[ShockerCyclone]

So I've never done a Sentinel run and I've been wondering about bonus powers for both 2 and 3.

Reave sounds like a really good power for 2 but should I stick with it for 3 or go to Dark Channel which I hear isn't as good.

Please note that I accidentally reset ME3 removing all achievements and bonus powers. I did a quick run with Ashley but I haven't unlocked Kaiden's bonuses yet so no Reave or Barrier available. I started a new soldier run but I'll do Sentinel if Dark Channel is better than Reave.

[The hot titan]

It depends on what difficulty you're playing. On Insanity I would recommend Energy Drain and ignore Overload. It's better because Energy Drain helps you keep Tech Armor up. You loose Cryo Blast, but you already have Throw and you don't need more CC on Insanity.

Another good choice would be an ammo power like Armor Piercing. Sentinel's kit already has everything but lacks offensive.

I'm not sure about lower difficulties. If you play on something where enemies are commonly unprotected you can get Shredder Ammo. This way you can get Cryo Blast scince it's more useful in lower difficulties, if you like it. You will spend points in Overload anyways.

The same applies to ME3, but now Reave can be used to detonate Biotic Explosions wich are really strong. If you don't unlock Reave you can use Dark Channel with the same purpose.

If you like to bring someone like Liara for her biotics or you don't do biotic combos for some reason, get something offensive like an ammo power, Carnage or Marksman.

[GreyKarasu]

Sentinel have decent ability setup. You alredy have Warp and Reave is only slightly better, you have Tech Armor - so no need for defensive like Barrier.
On insanity i highly recommend taking Warp Ammo (It adds a good damage vs almost everything + bonus against enemies being affected by biotic abilities) + you don't want take another ability with cooldown, you already have usefull abilities.

[ShockerCyclone]

I'm not playing on insanity I usually play on casual so I can be a little more creative with my builds but I've heard reave is awesome and dark channel sucks.

[GreyKarasu]

Well, on any difficulty Ammo Power would be one of the best choices (if not the best). Sentinel alredy have abilities vs any protection in game and Tech Armor for defense. And cooldown system in ME2 not optimal for many active skills.
And why even asking? On casual you literally can take anything - everybody dies so fast so you will notice no difference.

[The hot titan]

I don't have experience in casual but if you're most of the time fighting unprotected enemies you can take Shredder Ammo.

Reave is a great choice too, but does your Tech Armor get depleted often? If you take reave it's for Health regen when Tech Armor is down, and Sentinel is all about Tech Armor. It's not bad, i'm just saying. If my Tech Armor is down, the next defensive ability will always be Tech Armor. Reave has lower cooldown tho.

I agree with the other comment, get what you think is fun. Start bothering when you play on Insanity.

I imagine Dark Channel is very useful for a Sentinel in Casual. With one cast of Dark Channel you can trigger multiple Biotic Combos by killing the target when Dark Channel is up. This is much harder on Insanity because of the high health pool and protection.
A normal Adept goes Pull>Warp, Pull> Warp, While the Sentinel could cast Dark Channel>Warp>Warp>Warp. Its even better in larger groups where Dark Channel Is active on a horde.
As I said, I would choose Dark Channel only because of that. I say you give it a try.