104.3h In a multiplayer game, an effect that states that a player wins the game instead causes all of that player’s opponents to lose the game.
Is 104.3h a replacement effect created by the game rules, or does it modify the effect "win the game" on the card?
A different angle: Platinum Angel says "your opponents can't win the game". Does this refer to the game action "win the game", which instead causes your opponents to lose, or to actually winning the game? (or both?)
If 104.3h is a replacement effect, and "can't win" precludes following the "win the game" instruction, then nothing would happen. The event for 104.3h to replace didn't occur. I think this is the more likely outcome.
Otherwise, if we can follow the Maniac's instruction, then each opponent loses the game, except Platinum Angel's controller, because they can't.
Paraphrased from a comment for clarity: This question might boil down to "can game rules be replacement effects?" I haven't seen why not. The question I have regarding PA's effect is does it stop just the game event of "you win", or does it stop everything that, due to language, looks like "you win"? i.e. if 104.3h changes the game to mean the game action "you win" has nothing to do with winning, it might slip through, but if 104.3h is a replacement effect then it never sees LM's ability to replace it.
Further development: @ikegami commented: The confusion stems from the fact that 104.3h effectively turns "win (the game)" into a keyword action with a different effect than "actually winning the game". So which one does PA prevent now, the pseudo-keyword, or "actually winning the game"? or both?