Ehther, The Heavenly Monarch

As an additional cost to cast this spell, Sacrifice a creature.
When Ehther, The Heavenly Monarch enters the Battlefield, choose one—
•Search your library for an instant or sorcery spell and put that card into your graveyard. Shuffle your library.
•Search your library for a Royal creature card and put it onto the battlefield, it gains haste and "At the beginning of your next endstep, return this creature to hand". Shuffle your Library.