Raedric, the Silver King

Vigilance, Partner with Deirdre, Vengeful Queen
When Raedric, the Silver King, enters the
battlefield, you become the monarch.
Raedric, the Silver King, has indestructible and
hexproof as long as you are the monarch.
Whenever an opponent becomes the monarch,
sacrifice Raedric, the Silver King. You may play
any other commander creature for free.