Commander creatures you own have "At the beginning of your end step, exile up to one target tapped creature you control, then return it to the battlefield under its owner's control."
Ceremorphosis — When Illithid Harvester enters, turn any number of target tapped nontoken creatures face down. They're 2/2 Horror creatures.Tap X target creatures. They don't untap during their controllers' next untap steps. (Then exile this card. You may cast the creature later from exile.)
Choose a creature you control, then each opponent chooses a creature they control with equal or lesser power. If you chose a creature this way, exile each creature not chosen by any player this way.
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)I — Create a 4/4 white Angel Warrior creature token with flying and vigilance.II — Until end of turn, Angels you control gain ": Destroy target creature with power less than this creature's power."III — Angels you control gain double strike until end of turn.
Roll a d20.1—9 | Thunderwave deals 3 damage to each creature.10—19 | You may choose a creature. Thunderwave deals 3 damage to each creature not chosen this way.20 | Thunderwave deals 6 damage to each creature your opponents control.
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)