AmuletOfManyMinions/Corrupt Cell Staff

The Corrupt Cell Staff is a Pre-Hardmode staff that summons a circular, Demon Altar-like entity to fight for you. The summoned cell will follow directly behind the player, releasing bursts of mini-Corruptors, similar to the Scourge of the Corruptor, as enemies come near. Summoning additional copies of this minion will increase the frequency with which it summons mini-Corruptors. After at least 4 copies have been summoned, the mini-Corruptors will have a chance to inflict the Cursed Inferno debuff. Like other minions, the summoned Corrupt Cell is invincible and will last for an unlimited amount of time, unless the player dies, summons a replacement minion, or cancels the buff.

Its best modifier is Mythical for the widest array of set bonuses, or Ruthless for the highest damage output.