Use this card to get back "Iron Core of Koa'ki Meiru" or any "Koa'ki Meiru" monster in your Graveyard to help prevent the destruction of any "Koa'ki Meiru" monster on the field correspondent to the one in your hand.
Use this card's effect to return another "Koa'ki Meiru Crusader" to your hand then reveal it to keep it on the field (this doesn't make a difference since your opponent already knows you have it).
This card is especially useful if you are running "Koa'ki Meiru Valafar", since you will be able to draw normally if you keep destroying monsters.
Combine this card with "Creature Swap and any "Koa'ki Meiru" monster with 1800 Def or lower. Switch your other, "Koa'ki Meiru" monster to defense position, trade it for your opponent's monster, and then attack it with Crusader to get your monster back in your hand.