As a young child, horizon was separated from his parents in an attack from one of eggman's descendants, Dr. Scramble, putting up the biggest fight to find his family, constantly attacking Dr. Scramble, until Dr. Scramble, travels back in time, trying to prevent horizon from being born, resulting in a full rule over the planet, so horizon follows him back in time, to the timeline of Sonic and the gang to fix the future.
This leads to "horizon alternate futures" (a future game.) (I could also use help making the characters if you read this.) https://scratch.mit.edu/discuss/topic/369692/?page=1#post-3701018