Thread:Ultrasonic9000/@comment-1398428-20190105153029/@comment-477304-20190105155916

There aren't two Classic Sonics, all the characters treat him as the same character and likewise Classic Sonic acts as if he's familiar with them. Official bio descriptions even state that he's teamed up with Modern Sonic before. Lastly, Iizuka confirmed it outright at SXSW when asked by a fan.