I use Obsidian Mind, Scatter grenade, Shatter, Annihilation,Soul Rip, and Bloom.With a high intellect build, it's nonstop purple explosions. Be sure to run Surge at the Thrall maze, works wonders!

Bring someone with a full upgraded 331 Gjallahorn and Ruin Wings exotic gaunts. You will mow everything down and 2 shot crota to his knees when needed. Trust me, i'm the one that did it.

Yes. Personally I use sun singer during the lamp phase so I can throw solar grenades for my team to stand in when cleansing and also so I can Rez at the end if needed. If your team is good then run void walker and you will demolish this phase. For the rest of it I use obsidian with void walker because it does a ton of damage with all the thralls your super is half up after you set off your nova bomb. Also it's great on the sword bearer because it does decent damage and slows him down if you have the vortex turned on. It drives me crazy when I see two or three warlocks on my team running sun singer at Crota. They never use their super except when they die which causes an over soul any way and half the time causes a wipe regardless.

If a hunter can solo the entire thing..then I believe you can play with set you want and have success...don't let anyone tell you otherwise..there in no set way..play the way you want :)

Maybe in the beginning but I used sun singer and put on 2 solar grenades and that seemed to work wonders

The raid is simple with the right team. Any combination of arc/solar and a seeking rocket and you win.