Another idea:
(WARNING) Journey to One Spoilers
In the boss fight, Umarak takes Ketar and zips out of the Labyrinth. The fight takes place on the Labyrinth roof, with the Toa unable to unite (Pohatu is ideal for matching with the story). After the fight, Umarak loses Ketar and there is a small chase sequence across the island’s beach, but Umarak cannot be beaten.