Moris cooks up a potion for the banquet at the palace.
It turns them into Ninja Turtles.
They get into the palace, and see that Jagang isn’t in the throne room, so they ascend to the top floor, fighting Legionnaires on the way.
Uncas and Cyrus are the only conscious ones after a battle in the King’s bedroom, and Jagang pleads for them to end his life, he didn’t want to be a puppet any more. And to give Taven the robes in the closet.
Uncas stabs him in the (throat? heart? I don’t remember). And they grab Taven and Balin and slide down the palace walls.