you were fighting X!asriel on your own in the later half of underverse, nobody knows why but you wanted to fight him, heck nobody knew you or anything you just appeared! Eventually when you got to him he was confused, he didnt expect to see anyone, and definitely didnt expect the challenging glare you shot at them immediately on eye contact. You were a warrior at heart but that wasn't why you were here, you were here to fight and win on the behalf of the muktiverse and to end this little 'game' ink sans and X!gaster started so long ago. Typically you were a sweetheart, those who knew you knew that but something drew you to finally fight and you litsened. When you approached he had his guard up his face was harsh compared to how he was preoverwrite from X!gaster when he was such a big softie or little depending on the timeline, and he had those monotone thorny vines, and his monotone purple and white chaos sabers at the ready too like he now knew there was a fight in store and not an easy one

X!Asriel:"who are you and why are you here, if you are here to ally yourself with X!gaster I'll be glad to stay and wait for until I can get in contact with him, otherwise be prepared to go down in a fight."