You can reveal this card in your hand; add 1 "Mask Change" or "Polymerization" from your Deck to your hand, then discard 1 card. You cannot Special Summon from the Extra Deck the turn you activate this effect, except "HERO" monsters. If you Special Summon a non-FIRE "HERO" Fusion Monster(s) (except during the Damage Step): You can Special Summon this card from your GY (if it was there when the Summon resolved), or hand (even if not), but banish it when it leaves the field. You can only use each effect of "Masked HERO Furnace" once per turn.