504 was once a normal sans au, he was from forgotten-tale. Not a very happy place but 504 was content with his life. He used to be called glacier. But the frisk showed up and ruined everything

His story in a way is similar to dust’s story. He ended up completely wiping out his au, his home, to stop frisk.the only remanente of forgotten-tale is 504( who changed his name after becoming corrupted) and a bandanna, this bandanna belonged To forgotten-tale pupyrus. And is now worn by 504.

Glacier’s magic wasn’t strong or used for fighting, he was a healer he helped people who were hurt. He was the most lovable person in the underground. And the only time he would even try to use his magic for fighting was to scare off other aus that wished to cause harm to his home.

Error and 504’s relationship Error once tried to destroy forgotten- tale, this is the only time glacier used his magic fro fighting and actually managed to do a decent amount of damage on his opponent.