Sundial of the Infinite [Magic 2012] Fifth Dawn if your Spellcaster monster battles

if your Spellcaster monster battles an opponent's monster (Quick Effect): You can reveal any number of Spells with different names in your hand

Cannot be Special Summoned

When an opponent’s monster declares an attack: You can have this card lose exactly 1000 DEF

but I didn't expect it from the building itself

If this card attacks a monster

Sundial of the Infinite [Magic 2012] Fifth Dawn if your Spellcaster monster battlesSet: Magic 2012 Type: Artifact Rarity: Rare Cost: {2} {1}, {T}: End the turn. Activate this ability only during your turn. (Exile all spells and abilities from the stack. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)