Joraal, the Darkin Aegis

Soulbound (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)

As long as Joraal, the Darkin Aegis is paired with another creature, each of those creatures has "At the beginning of combat on your turn, create a token that's a copy of this creature, except it has haste and loses soulbound. Exile it at the end of combat."