I only use my stacks on Lustrate
Adlo Tank before each and every DS
Lustrate as soon as the Death Sentence cast is finished (take few time to get the right timing)
I use EfE on cooldown
Succor before fireball
Fairy Rouse/WD pretty much on cooldown as well during phase 2

P3 I used i sacred soil on each spawn, focus on keeping the 2 tanks alive then, when things look clear, put some dots on the snake
Get in position and pretty much use all your mitigation: Succor, Adlo the tanks, Rouse/WD/Fey, Sacred Soild, Virus on Twin

P4 only focus on tank. No trouble unless she use DS straight after twister. I place fairy close to tank so WD can also touch him and Adlo/Lustrate before/after each DS

P5 Use everything you have you keep tank alive