2x Zaan/Maw of the Infernal: Head(heavy/divine/magicka), Shoulder(medium/divine/magicka)

5x False God, Roaring Opportunist or Necropotence: Chest,Pants,Hand,Belt,Shoes(divine/magicka)

5x Medusa, Mother's Sorrow or Infallible Mage (Always tell your Healer you're running it!):
Lightning Staff (precise/flame), Jewelry(infused/spell damage)

1x Maelstrom Flame Staff (infused/weapon damage)

Food: Solitude Salmon-Millet Sauce (Blue Max Health+Max Magicka) or Artaeum Pickled Fish Bowl (Purple Max Health+Max Magicka)
Potions: Spell-Power Potion (Spell-crit, Spell Damage, Magicka)


Rotation:
Above 50% of health:
Lightning Flood > Light Attack > Unstable Wall of Elements > Weapon Swap > Light Attack > Daedric Prey > Light Attack > Volatile Familiar > Light Attack > Twilight Tormentor > Heavy Attack > Structured Entropy > Weapon Swap
Restart

Below 50%
Lightning Flood > Light Attack > Unstable Wall of Elements > Weapon Swap > Light Attack > Daedric Prey > Light Attack > Volatile Familiar > Heavy Attack > Structured Entropy > Heavy Attack > Weapon Swap
Restart

Use crystal fragments whenever it procs to perform an instant cast.

Ultimate:
Use the Atronach on boss fights and Shooting Star on trash fights.
Shooting Star can be switched with Elemental Rage if you want.
For selfheal you can use Twilight Matriarch instead of Twilight Tormentor or Critical Surge.

Flex Spot Slot 4= Bound Aegis, Mages' Wrath, Boundless Storm, Critical Surge