Kajja, Merchant of Betrayal

At the beginning of your upkeep, if you own
Kajja, Merchant of Betrayal, gain control of each commander on the battlefield until end of turn.
Untap them. They gain haste until end of turn.
At the beginning of each player's upkeep,
that player gains control of Kajja. Untap Kajja.
Commanders must attack their owner
each combat if able.