Darkness Destroyer [GX06-EN003] Super Rare 213 and they cannot be destroyed

and they cannot be destroyed by your opponent's card effects

At that time

Set: Force of the Breaker Card type: Effect Monster Rarity: Ultimate Rare Attack: 1600 Defense: 1500 You can discard this card to the Graveyard to add 1 "Necrovalley" from your Deck to your hand

except for its own effect

(You do no use "Polymerization")

Darkness Destroyer [GX06-EN003] Super Rare 213 and they cannot be destroyedSet: Yu Gi Oh! GX Tag Force Promotional Cards Card type: Effect Monster Rarity: Super Rare Attack: 2300 Defense: 1800 Cannot be Special Summoned. This card can attack twice during each Battle Phase. If this card attacks a Defense Position monster, inflict piercing Battle Damage to your opponent.