Tech only sentinel?

My Sentinel build was Lance+Energy Drain+Incinerate. Shield powered Lance, lots of shield recovery. Endless combos and really hard to kill even on insanity.

A pure tech Sentineal should work OK at high levels, you'd just need to invest in biotics enough to level your profile even if you're not using it (and Barrier would certainly be useful of course). Take advantage of the combo damage boost - so Energy Drain and Incinerate set to both prime and detonate and then something else that either primes or detonates would be good I guess.

Primer dictates the type of combo I think, so a singularity based combo would be biotic

As Derrame said.

Sentinel is someone with Biotics and Tech, but very little combat (ME1 Sentinels were basically combat life savers and support troops). You wanna take the Biotics away, you got a plain good ol' Engineer.

The six original classes, as they went were (their signature powers from ME2 onward in brackets):
Soldier - Full Combat (Adrenaline Rush)
Engineer - Full Tech (Drone)
Adept - Full Biotics (errr, Throw? I think Vanguards had access to Singularity and Warp)
Sentinel - Tech/Biotics (Tech Armor, because it used to be a regular power)
Vanguard - Combat/Biotics (Biotic Charge)
Infiltrator - Combat/Tech (Tactical Cloak)


To build a good ol' oldschool Sentinel, you're investing in pistol passives and end there, play it power heavy. Oh, and be glad Tech Armor is now passive, because you don't need to use a slot for it.

The problem is that if you take only tech powers you can't raise your sentinel profile
You can take Barrier since it's alays useful,but other biotic passives improves active abitilies. maybe later in the game when you have maxed your tech abilities (you don 't need more than 3+3 passives) you can spend points in some biotic abilities that you won't use.