Special Summon this card as an Effect Monster (Rock-Type/LIGHT/Level 4/ATK 1000/DEF 1800). (This card is also still a Trap Card.) While this card is an Effect Monster, if another Trap Card you control that is a monster would be destroyed by your opponent's card (either by battle or by card effect) and sent to your Graveyard, you can Set it in the Spell & Trap Card Zone instead.
How to Get
Treats Trap Cards as monsters
Special Summons itself from your Spell & Trap Card Zone
Don't worry. If there are 2 copies of this card on the field, you just destroy both. The first one goes back to the spell and trap card zone, but because they are traps they cannot be activated the turn they are set so if you then attack the other one then that one gets send to the graveyard. You can also you effects that remove the cards from the field or tribute them.