So
Y e a

Lore:
So sonic was popular, he was the favourite of all until.
Tails appeared
Tails was
Normal actually he was a great Pal and an excellent mechanic, people liked him more than sonic,the people was forgetting about sonic and them was just playing for the new character, sega added more characters like, knuckles, metal sonic, amy and
Sonic began to go mad cause he got jealous about how people liked other characters.

After a few weeks amy disappeared, she was found in a street with no legs and his eyes out And with the jaw torn off
Knuckles and Tails couldn't recognice her.
Sonic was there but he didnt have expression about it, Knuckles had suspicions about him since he didn't speak lately.
Knuckles baited sonic going to an alley alone, sonic appeared with a very deformed smile, knuckles was scared but then tails came to the place since before knuckles called tails to that same place because he knew that sonic would go there to kill him and so he would have sonic and tails in the same place.

Tails confronted Sonic but sonic said that no one could be on the spotlight, only he and only he can be the one on the spotlight, Sonic said that if he can't be the favorite, NO ONE WAS GOING TO BE.
He made a whirlwind with his speed and leaving clueless both tails and knuckles

Sonic escaped and was never seen again.
Sega had a plan and they brought another sonic, this sonic was longer with long spikes and his eyes were green.
The original sonic was never heard from again but tails missed him because he was his best friend.

Note:
All this takes place before the dreamcast era
Sonic replacement is dreamcast or modern sonic
Sonic replacement is a sonic clone that they made based on sonic dna

Pd:
Sonic looks like a Sonic. Exe take lol