While this may sound insane by Porn Game standards, most narratives do not give a shit what the audience think. If you put down every book when a character you like dies than I can only imagine how few books you manage to get through.> Don't have malice
A. Heresy of the highest order. This game sole reason for existing is Malice.
Malice is Love. Malice is Life. Malice is the best character by far. This game should be renamed to include her name in the title. Something like "Malice's Story"
B. metagaming: MC explicitly does not know anything about a cataclysm in character until after having Malice. At which point it is unstoppable.
C. spoilers: There is zero indication that the Cataclysm is going to mutate your LI into hideous abominations. As the game is very intentionally vague about what the Cataclysm actually does.
D. time travel: This content was just added. So while future players have the possibility of getting spoilers (which are a can of worms), current players had no way to foresee the future and know this is what is going to happen to their waifu.
E. We are given a false choice. We can say we don't like it, and it happens anyways.
If Malice is your #1 girl there is a path for you.
If Heliose is your #1 girl there is a path for you.
If Marie-Anne is your #1 girl there is a path for you(or two if you like deer).
Being unhappy that you can't get every girl to do exactly what you want them to do is short sighted.