During your Main Phase: You can add 1 "Red Dragon Archfiend" or 1 card that mentions it from your Deck or GY to your hand, except "Crimson Gaia". When your "Red Dragon Archfiend" declares an attack: You can change all monsters your opponent controls to face-down Defense Position. If a monster(s) on the field is destroyed by battle or card effect: You can Special Summon 1 "Red Dragon Archfiend" from your GY. You can only use each effect of "Crimson Gaia" once per turn.