The only way I can think to salvage this shitfest is the alternate ending where Zoey wins:

-Mike and the alters defeat Mal and suppress him with them going away. Mal isn’t destroyed forever because that’s not how it works, but at least Mal is locked away again.

-Mike helps Zoey win because he knows he should not win on account of Mal doing all the work and it not being of Mike’s own merit.

-But actually Alejandro and Heather steal the million and ollie outie before the island sinks.

-And it ends, showing the contestants from the balloons on Pahkitew Island, which is how Chris finds the location for the next season.