Thread:RainEStar/@comment-24541035-20160203222507/@comment-25077685-20160302014856

What about this?

Evolve: Return a rear-guard to your deck, search for a card with one grade greater than the returned unit, and call it to (RC).

Let's say it's Time Leap (From Gear Chronicle) that keeps the new unit for the rest of the game instead of returning it back to the deck at the end of turn.