FLIP: You can target Set cards on the field, equal to the number of Subterror Behemoth monsters you control; destroy them. You can only use this effect of Subterror Behemoth Stygokraken once per turn.
When a face-up monster you control is flipped face-down, if you control no face-up monsters: You can Special Summon this card from your hand in Defense Position. Once per turn: You can change this card to face-down Defense Position.