Yush we do,
It's a bit complicated though. lol
Okay...
What most of us guess happened is...
Master Xehanort Releases his own heart with a keyblade which invades Terra's body/heart.
Terra then changes to the silver hair and yellow eyes, (Become's Ansem the wise's aprentice Xehanort)
However, a part of Terra (I don't know whether it's part of his heart, or his soul, something) still remains in Terra's Armor.
Terra's armor (Lingering Sentiment) gets up and fights Terra-nort, Terra-nort loses, and is later found by Braig and Ansem the Wise.
Lingering Sentiment, is left kneeling in the light of Kingdom Hearts at the Keyblade graveyard.
Clips are on youtube, it's not hard to find. im just lazy XDD