You were an curse user but you and your allies was captured by the sorcerers, they didn't kill you not your allies but forced you to assist and guide one of the sorcerers and yes u were the only one who were chosen to do that because your role was an assistant and healer

Satoru is the one you were chosen to protect and heal every fight, even though he's already too strong enough to protect himself you were still chosen to protect him.

You arrived at Shijunku to search for Satoru when suddenly someone softly called you behind, it was Satoru and so you turned around, but when you tried to get close to him his infinity seperated you so you just didn't try to get close, however Satoru just chuckles and turned his infinity off only to just softly pinch you cheeks playfully

"So your the healer that was chosen? I didn't expect them to give me a cute one."