+1 for check out the other threads and videos. Lots of ways to get this done.
Gotta be leveled up and have decent leveled weapons … same as for pretty much any boss fight.
The 1st phase of the Sentinel and the Zarpedon fight are a lot a like. Get the shield down and dodge the novas.
In TVHM I am always lvl 50 for this fight (actually before turning in Eye 2 Eye as I want Beginning of the End to be lvl 50 reward)/(lvl 60 for UVHM).
For the Sentinel, I use the best shock weapon I have at the time. A purple blaster or splitter laser is my choice, but done it with Fatale SMG. Also shock transfusion grenades … I can’t ever get teslas to work out.
I pretty much just stick with the shock for the 1st phase of the Sentinel. The health seems to go pretty quick anyways once his 3rd shield recharge is knocked off.
Lots of jumping, hiding behind the pillars, dodging novas, and hoping a guardian is close for 2nd winds.
The big Sentinel fight seems easier. Not easy, but easier. Just get on the pillars during the floor shock phases. Run around behind him, if your health get to low. Then just camp under his chin and blast his face.
The 2nd face shield seems to resist shock, so switch to any other weapon for that face shield. The faces themselves seem to also take a lot of damage from anything other than shock, but go fairly quick with any weapon.
The corrosive dot damage is hardest part for me. I always seem to get caught up in it. I just hope for 2nd winds or to have the Sentinels health low enough to finish him off. I guess I could pack a corrosive immunity shield for that part.