Sil'goruc, Cruel Overlord

Worship—Discard a card or sacrifice a nonland permanent. (Whenever another creature enters the battlefield, its controller may pay this creatures worship
cost. If they do, that creature is worshiping this
creature.)
Flying
At the beginning of each opponent's upkeep, that player loses 2 life for each creature they control
that isn't worshiping Sil'goruc.