Steam Fighter, Mesh-he

(This ability is active if you have one or more face up G units in total on your or G zone): 1 When your opponent's rear-guard is put into his or her deck due to an effect from one of your other cards, you may pay the cost. If you do, choose a card from your damage zone, and turn it face up. (Even if you do not pay the cost, this ability cannot be used for the rest of that turn)