Stack vit, 6k + on healer = easy burn for every boss including siren herself lol.
I never attempted it till i did one day as i was purely basing the success off of the other boss fights in PS.

1st boss adds are easy to kite.
Just make sure that you're
-always moving on the outer rim
-always time your explosions so that you won't explode near dps/ tank. ( most likely they will be near death due too most ppl having hp from 3500-5000 hp.
- if the corrupted crystal circle AoE is already at growth stage #3, run into it and stay within the crystals as you will only get one stack once u enter it.
-exploding is inevitable, so always remember to be at full hp + any damage mitigation / defence buff.
- always have HoTs up on yourself and party.

And zu is just like turn 2 enrage lol....