Most likely Xemnas is refering to Ven.
And on an other note, anyone see/remember the scene where Xemans was talking with Roxas on the Dark Beach in the Dark Realm, and he he put his hand on Roxas's shoulder as he left. Well that mirrors an exact scene in BBS where Terra does the same thing with Ven.
A cryptic hint or what?
can you provide a link to this video?