So with this new trailer we see all forms of Xehanort are in the game (MX, Ansem SoD, Xemnas, YMX, and reborn Xehanort [terranort]). Im sure this game will somehow explain "where" terra is cause evidently noone knows yet and this will be discovered through all the Xehanort forms. Also though im thinking if YenSid said MX would return in his original form wouldnt he mean the reborn Xehanort cause if not that means Terra is s.o.l.