Whether this "saves the world" depends entirely on which side of the fork the story falls on.
There is no "dense protagonist" wondering who to choose. He must choose all of them to survive. The polyamory is a mechanical necessity for the salvation of the world, giving the genre conventions a lore-accurate justification. harem fantasy good or evil will save the world fix
The 100 Girlfriends Who Really, Really, Really, Really, Really Love You My Next Life as a Villainess Whether this "saves the world" depends entirely on