Hey dude, I made a back story for a error version of mr xand. Come take a look:
As time passes and finishing his bucket list.
Mr xand increasingly got bored, he then decide to do... something new.
Through out infinite numbers of screens, viewing xands through out existence. All with their own story and life.
Mr xand, with his omnipresent. Is able to see and experience every single xands. Like having infinite of him/clones or versions. He alone was the only one.
Having a curiousity to kill the cat, he begins his experiments. Whether it's for good or bad. His curiosity never seems to go. After all, he can just "reset" everything and start over.
On one particular moment. After getting interested in the Undertale universe and it's many many AUs and ATs. Why not try one himself.
And so, Mr xand went to experiment. Trying clones or versions of himself. Finding interesting or underwhelming results. He continues on.
Eventually, the multiverse of Undertale begin to treat these xands as part of their multiverse. Creating many AUs and ATs of different xands.
Because of that, Mr xand finding this amusing and interesting. Decide to put a clone of another xand of this multiverse to the anti void.
After sometime, Mr xand detailing the xands transformation. Has now because the error! That he is was expected to be.
Through, he might not have the same traits and personality as error sans. He has satisfied with the outcome.
And so, dubbing this. As original as possible:
Error! Xand.