Magic weapons — staves, spellbooks and magic guns — trade mana for versatile damage: piercing, homing, area-of-effect and utility no other class gets. Keep mana potions and mana-regen gear on hand to fire them continuously.
The Last Prism, a Moon Lord drop, tops the class with a sustained solar beam. The Nebula Blaze, Razorblade Typhoon and Bat Scepter are strong picks going into the fight.
Each cast drains mana; run dry and you stop firing until it regenerates. Mana potions, the Mana Flower and mana-regen accessories keep magic weapons firing through a boss fight.