Why do you depict Chara as the villain here? In the game there is absolutely nothing to suggest that. Think about it. If they're really so bad then why did Chara reset the timeline so that you would be forced to go through again and most likely not kill everyone. Why would Sans be able to remember when Flowey can't and Flowey has the most determination seen in a monster. Oh wait, Chara warns him and communicates. They also do the dialogue. They translate froggits and make the thing easy.
Actually I think you may have missed a thing XD. It’s cool though. I shall explain best I can without giving away things-
This is actual Chara as depicted in this comic.
Chara doesn’t look a whole lot like this-
-red nightmare child, do they? However this ^
Sure looks a whole lot like this kid we see here below. Like Frisk.
I have to be sorta vague for plot reason but just keep in mind in game Sans never sees Chara as we, the player, saw them.
Better yet he never saw the player either, did he? >D
And where is he seeing this red kid?
In a nightmare.
But Chara, the leaf child with the locket, is nowhere near the villain of this story =U