Postby Enjl » Fri Aug 21, 2020 9:56 am
Technical explanation:
There are three errors that are at play here:
1) Certain new characters aren't designed player-slot-agnostically, meaning they access the first player regardless of which player is actually playing as that character.
2) The global Defines variables such as Defines.gravity and Defines.player_grav are, well, global. Some characters alter these, having an adverse effect on simultaneously used characters in other slots.
3) Multiplayer with certain character combinations that even don't fit into the other categories can be broken, because internally the new characters re-use the character IDs used by the basegame characters. So if you use Peach and Uncle Broadsword it would work moderately fine, as Broadsword uses Mario's ID under the hood. But Broadsword and Mario would cause errors, as would Mario and Wario.