The only sin Chara made was letting the genocide route corrupt them, and thats thanks to the player.



I kind of wish they actually were brought back with their own determination more than aything and fight the player.



Don't get me wrong, I do like anotganist Chara's, Just not the ''All-out evil villain'' Chara's who make no sense to me.



But I do like two-dimensional Chara's used on AUs and etc. and I like the idea of Chara getting a redemption run.



I mean there are a couple of things I wish that happened on Undertale:



Sans fighting you when he realises you are going to do genocide/ After you kill Papyrus but his attacks are fairly harder to dodge due to him being angry.



But then again, I personally have a headcanon that Sans was fighting off Flowey, Who goes in first to do all the puzzles for you in the Genocide Route and giving the other citizens that Flowey was trying to kill time to escape, managing to beat Flowey again and force him to pull back/retreat.



That would fit him and explain why he only fights you at the genocide route at the end.



As for the neutral routes...I still wish he fought you...It almost looks like the system of the game or something was holding him back...like a barrier.