(Deathly Basilica isn't a spell.)

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

Deathly Basilica is indestructible. (Destroy effects and lethal damage don't destroy it.)

: Add  to your mana pool. Return Deathly Basilica to its owner's hand.