He took a youngsters body ( Terra ) and took it over to pre long his life once his nobody and heartless form where defeated his old man form strangely formed again. You would think terranort resurfaced instead of the old man but its KH lol.He most certainly was mentioned in 2 but the intrigue is in why he was a young man in KH2 but was an old dude in BBS, which took place 10 years prior to KH1.