Recommend a 3rd Power

Annihilation to set off your charge. Boom!

Seconding Energy Drain. My current set up is Cloak, Charge, and Energy Drain. It helps when in close combat.

There was a mod for ME3 that let you use MP powers in SP. I set my Vanguard Shepard up with Annihilation; it was really overpowered (since the Charge did detonate Annihilation), but also really fun lol. I was sad that I couldn't do the same in MEA when I saw it was available, but I can understand why

Not to be a dick but I don't see see much reasoning for Energy Drain.

Charge and Cloak grants more than enough survivability.

Aww, that's disappointing, I was thinking of making a build based around that. In ME3MP I loved using the Fury, just running around using Throw whenever I got close to an enemy for an instant Biotic Explosion. And Dark Channel for even more explosions!

With the significant cooldown penalty Annihilation (Field - why'd they remove the Field part?) has in ME:A, I'm not sure if it would be nearly as useful.

This feature combined with the Vanguard profile's melee vampirism is quite effective. Although I'm sad the sword isn't nearly as good as it was in ME3MP since it lacks both light and heavy melees.

Apparently I miss ME3MP Anyway, I also like Energy Drain. If specc'd appropriately, it can prime and detonate.

You could bypass the cooldown penalty, if you use the Fusion Mod of Adrenaline. I don't like using them before obtaining the cryoperk that halves their penalties. Still, once equipped, they're insanely good.

I think Energy Drain is one of the very best powers in the game. A Sentinel with this skill is nearly impossible to injure. I'm playing one now, and suspect that my skills will be rusty in my next PT as a result. I'm so used to being impossible to kill that I'm walking around in the open during battles. Most of my other favorite builds would be shredded if I did this.

maybe not the best but shockwave can prime and detonate. (same with incinerate)  It can also help with clearing anyone out from close to mid range, and it's fun with charge.

Throw Shockwave, cloak, then charge to set off combo and shoot or melee for additional damage with charge and cloak passives active (use adept profile for additional explosions).   Bring Cora with her cryo ammo for even more fun or Pee Bee to use pull for more biotic combos. 

Otherwise I would suggest Cloak, Charge, and Turbocharge using the explorer profile with a Piranha equipped.

I was disappointed with Annihilation too at first coming off the insanely fun Fury. Cooldowns so bad it was basically useless.
But now everything dies within seconds when I detonate with Lance rather than Throw. But I'm playing on Normal, Patch 1.05 still. Will try how my build fares on higher difficulties soon. Even with health/shield buff armor (Hyperguardian or N7) I'm a glass canon. I die as quickly as the enemies if I'm not careful... ME3 was so easy as a vanguard I'm being a bit careless perhaps. Not bothering much with cover. Just zipping from enemy to enemy until they're all dead.^^

I specced Annihilation for reduced recharge penalty on my other powers. Haven't put any points in the remaining two evolutions. Don't seem worth it.
I specced Lance for zero cooldown but 50% shield usage (like Nova was before, only if you have no shields you cannot use Lance at all, that's the downside of this evolution). I replenish the shields with Charge. Took 75% quicker cooldown. This way I can almost instantly charge again. So Annihilation/Lance becomes an almost nonstop biotic explosions frenzy. Switch it up with some melee punching.

It's a super fun build. Charge/Nova (specced for priming)/Lance is fun too. Both on the Adept profile. I have the biotic passives almost maxed now (I'm still fairly low level, 25 or something). Specced for maximum biotic damage. I don't shoot my pistol much. Just finally got the Talon I used on the Fury. But the sound is different and I'm SO disappointed, lol.

Well, depends what you feel is missing and if you want to help your melee or sniping.
If you don't really feel like you're missing anything and don't want to bother with combos a combat power is always a great pick. Flak Cannon is amazing now, lots of damage and can either aoe stun anything or melt armor. Omni Grenade hits hard as hell and Turbo Charge is the bomb.
Invasion is also great, you can cast it, go into cloak and hit hard as hell. Cryobeam/Flame Thrower are also great when you go melee and will let you prime stuff.

Honestly i'd probably just set up 2 profiles, 1 Infiltrator/Soldier profile while sniping and a Vanguard one for charging/melee.

Remnant VI. At the very least, it's a good decoy. Also it's able to follow enemies through walls (though, killing them takes time).

Using an Asari is like a 3rd power.

It comes with invincibility frames. The slow speed of the strike acts like a super fast cooldown.

Now I understand why I barely use my 3rd power.

That's not a bug, it just wants to be your bestest friend.

So if one day the Pyjak disappears ... don't be surprised.

PoC can be quite useful when the unexpected happens, for example leaving the Nomad from the right hand side, not the usual left, and finding you are right in the firing line and trying to get into non-existent cover. The more targets the enemy have, the better.

Ryder's cry "You three attack them while I get out of sight." should have been included in the game.

It depends a little on how you evolved the Charge power. If you took the option that gives you a power damage bonus for 5 seconds after charging I'd go with a good up-close power, like Shockwave or Flamethrower. If you took the weapon damage bonus evolution you'd be better served with a power that primes enemies for combos that you can in turn trigger with Charge; Incinerate is good, Lift and Singularity are also great.