(Sulfurous Ampitheater isn't a spell.)

At the beginning of your end step, if you didn't cast any spells this turn, Sulfurous Ampitheater deals 1 damage to you.

Whenever a card is put into a graveyard from anywhere, exile that card.

, : Add , or to your mana pool. Sulfurous Ampitheater deals 1 damage to you.