Steel Fly

Steel Fly is a unique familiar summoned by the Steel Ball weapon item, which can be used once per battle to deploy it. With 1 HP, 2 damage, and 4 movement, its raw stats are identical to a regular Fly. What makes the Steel Fly exceptional is its complete invulnerability to standard damage and status effects. No conventional attack can destroy it once summoned, making it a persistent battlefield presence that cannot be removed by normal means.

The Steel Fly targets bleeding enemies preferentially and gains bonus action turns for each bleeding unit on the battlefield. This creates powerful synergy with bleed-focused builds: the more enemies you keep bleeding, the more turns the Steel Fly takes, rapidly multiplying its damage output. It shares this bleed-chasing mechanic with Baby Shark, and combining both in a bleed-heavy composition creates an overwhelming cascade of bonus attacks each round.

The only known way to remove a Steel Fly from play is through instant-death abilities, such as Daddy Shark's consumption attack, which instantly kills anything it can reach regardless of invulnerability. When facing an enemy Steel Fly, this is the only reliable counter. When using one as an ally, pair it with Bleed-inflicting abilities and items to maximize its bonus turns. The Steel Ball's once-per-battle limitation means timing the summon is important: deploy it when multiple enemies are already bleeding to get immediate value.