Who are the 3 keyblade masters
there are technally 5... sora, riku, roxas, mickey, and terra. But roxas is apart of sora so kinda 4... so yah
wrong, i can count :P
ven, terra, aqua, mickey, sora, riku, kairi, xeon, xehanort
the keyblades not so special xD also, remember, genie made a keyblade when u summoned him :P
Question Improved
There's Ven, Terra, Aqua, Mickey, Sora, Roxas, Xion, Kairi (Apprentice ( I Think)), Riku NOT Xehanort
Improved:
Although many think Sora is, he really isn't. He is chosen by the Realm of Light's keyblade and can connect his heart with all others, but he isn't a Keyblade master, yet.
There are 4 actually: Master Eraqus (The guy who teaches Aqua, Ven and Terra), Master Xehanort (The main antagonist of the KH series and the guy who teaches Vanitas), Master Yen Sid (The guy in the tower in Traverse Town who teaches Mickey), and soon-to-be Master Aqua.
Aqua becomes a keyblade master when she is the only one of Master Eraqus's apprentices to pass the Master Qualification Exam in Birth By Sleep. Ven is too weak, and Terra loses to Aqua and is proclaimed to have to dark a heart to be a master.
As that may be if you look very closely at some of the keyblades that sora doesnt obtain u can clearly see that kairi's keyblade therefore making kairi an APPRENTICE! yet both sora having been in every KH game and quote from Donald in COM "cheer up sora, you are the keyblade master after all" making SORA a keyblade master and how does KING MIKEY not get to be a master
The Truth and Extra Information
The three masters to be announced as the first keyblade masters were Eraqus, Xehanort, and Yen Sid. Later Aqua was annouced as a master but not Terra due to his darkness in his heart. Xehanort trying to get on his good side, gave the title of master to Terra near the end of his story arc. Mickey is not a "master" of the key, but I am sure he has the material to do it. In the near future, Sora becomes a master in KH2 FM+ when you beat Terra's Remnant who says he recognizes you as a keyblade master. Roxas is a direct nobody of Sora which makes him in a sense a Master as well, but Riku is not a master for no one has recognized him to be yet. Kiari is just a new apprentice to the keyblade, since the second game. Hope my information was able to help you.
-Kidoshi
improved again: currently master yen Sid, aqua, master xenhort, master eraquas, and more to come in kh3 he mark of mastery is held again by master yen Sid