Xoone

Echo Star, AKA Xoone and Master Nopony, is a Nobody, and former Equestrian unicorn, from the time of Clover the Clever and a former friend of hers until he was caught abusing memory spells by his friend and using it to do whatever irksome thing he wanted because of his arrogance and selfishness, becoming the creator of the Memory Stone. But when he was fired and shunned by everyone, he continued recklessly using the Stone to destroy memories specifically of Clover as revenge for 'betraying' him, and eventually almost destroyed Clover's own life and memories until the final chase threw him into Human Equestria, where he hid away the Memory Stone after learning there was no magic there. He had since went missing while the Memory Stone would be found and abused by Wallflower. Throughout this time, his tampering with dark magic caused him to lose his own heart and his own self, turning him into a breed of Nobody called a Nopony, which is when an Equestrian pony loses their purity to Kingdom Hearts. He has since become a rogue sorcerer who sought to have his own existence forgotten out of regret and start over again as his pony purity was still remnant and making him an emotional mess.