Subterror Final Battle

Activate 1 of these effects, also, after that, Set this card face-down instead of sending it to the Graveyard. - Change 1 Set "Subterror" monster on the field to face-up Attack or Defense Position. - Change 1 face-up "Subterror" monster on the field to face-down Defense Position. - ATK and DEF of 1 "Subterror" monster on the field become equal to its combined original ATK and DEF until the end of this turn. - This turn, activated effects of "Subterror" cards cannot be negated.