I present to you...
Classic!Ezekiel & Classic!Aaron !!!
Instead of traveling to the future, Classic!Ezekiel is a ghost that hangs around Classic!Knuckles, he gives him advices and company.Sadly others can't see him only Classic!Knuckles does but he can use this as a advantage to prank the others.
He also help Classic!Knuckles on hidding the Master Emerald by telling him the best hidding spots.
Classic!Aaron is more of a introverted than Prime!Aaron, being isolated and do the things for himself, but Classic!Sonic have other plans and always drag him with Classic!Tails to hang out which sometimes he is annoyed because of them but enjoyed their company even though he doesn't want to admit it.