Gagaga Cowboy [AP05-EN002] Ultimate Rare Effect monster and if you do that

and if you do that

halve the monster's ATK until the end of the Damage Step

inflict damage to your opponent equal to the ATK the destroyed monster had on the field

also you cannot Special Summon monsters for the rest of this turn

you can remove from play 1 card from your opponent's Graveyard

Gagaga Cowboy [AP05-EN002] Ultimate Rare Effect monster and if you do thatSet: Astral Pack 5 Card type: Xyz Effect Monster Rarity: Ultimate Rare Attack: 1500 Defense: 2400 2 Level 4 monsters Once per turn: You can detach 1 Xyz Material from this card; apply this effect, depending on this card's battle position. Attack Position: If this card attacks an opponent's monster this turn, it gains 1000 ATK and the opponent's monster loses 500 ATK, during the Damage Step only. Defense Position: Inflict 800 damage to your opponent.