i don't think they quite understand that was a temple "i believe the name is eclipse temple" its designed to cleanse you mentally of your strife.... that fight was all in sonics head, he was never in any danger...... even sega was there over seeing it...... the jist of it is that temple was a factory reset without losing you personality......it was a way for sonic to become new again.....
im assuming this au hasn't met the sega ceo yet its probably a pre sega sonic..... so like before sonic adventures 1 or 2 when he had to come in for a "Reboot".... and sega changed his eyes from black to green....and him from short and stubby to long and lanky...