Must be tribute summoned by using a Steelswarm monster as tribute to use effect.
Pay 1000 LP to revive.
Steelswarm monsters are made up of 2 kinds of monsters, the low leveled monsters that should be used as tribute fodder, and the powerful high-leveled monsters who gain effects when you use Steelswarm monsters to tribute summon them. Additionally, when tributed Steelswarm Caller and Steelswarm Gatekeeper allows you to swarm the field with Steelswarm monsters.
Here are the monsters you should use as tribute fodder: