• Chara is a robot like Mettaton

So basically the backstory would be the same except Alphys managed to save Asriel and Chara came back using Asriels determination. Alphys built a body that resembled them and Chara hopped in. They have emotions and all that as well, but not a SOUL so they can't be killed, you can only break their body. If you break their body they're a ghost again and won't affect pacifist but it will affect true pacifist.

• Chara never died

  Chara never tried to poison them self, thus preventing them from possibly dying.

• Chara becomes a ghost

  Basically the robot thing but Alphys never built the robot and Chara can actually do damage to you as a ghost.

Vote your favourite idea and it'll be official. Have a nice day!