Underworld Prison

Enchant player.
Underworld Prison has shroud.
Permanents can not deal damage to you.
At the beginning of each upkeep exile all nonland permanents you own under Underworld Prison.
At the beginning of each end step, Underworld Prison does 1 damage to you then sacrifice a land.
Pay half of your life sacrifice 3 permanents: Sacrifice Underworld Prison and create 3 2/2 red demon creature tokens with flying.(Only if Underworld Prison has dealt 7 damage