Activate by removing 1 face-up Fusion Monster you control from play. Negate the activation of a Spell or Trap Card, OR the Special Summon of a monster and destroy that card. During your 2nd End Phase, return the removed Fusion Monster to the field in face-up Attack Position.
Probably needs to be exactly 1 monster, not a bunch at once.
I've started using this in my Red Eyes slash dragon and it's a really good card for this deck. One weakness Red Eyes slash can have is when you go first and summon it on the first turn. With this card it removes that weakness from your card being destroyed or flipped down etc.
It's almost always going to be worse than running an Equip Card. It's only going to be particularly good when the opponent is going to Summon something much bigger than Slash Dragon, like a Quintet Magician or something.