Shi is half human, half monster (younger me thought it was a good idea), with their soul breaking/cracking from the magic they wield, it being stronger than their body can handle, and trying to flee from their home after they were found in, after so many years of living in the security of their home with their parents, till their father, who was a monster with illusion magic was found out and killed. as soon as they got into the underground, they met the spirit named Kai, who attached themself to Shi's soul, connecting them together. Kai was able to manipulate and take control of Shi's actions when he wanted to. Kai was a human that fell into the underground before Shi. after going through a 'genocide run' in the underground in their Au, they met Ink Sans, who took them to a different Au to cheer them up, after finding them in the doodle sphere, well they were trying to get through the barrier in their Au. Shi met Ryu!Sans, and Asher!Sans in the Au, Ink Sans took them to. after a month they became completely corrupt, and attacked Ryu!Sans, killing him, ultimately betraying him, then they attacked a skeleton named Asher!Sans, giving them scars but not killing them. after they killed Ryu!Sans and attacked Asher!Sans, they were found in the forest of Ryu!Sans' Au by Nightmare Sans and was taken into his gang, as their personality went from sweet and friendly to sadistic and hellbent after becoming corrupted completely.