Sora...... is the man protagonist in the series. Roxas is the nobody (look that up if needed) of Sora. Ventus is not related to the two, but his heart remains in Sora after his fight with Vanitas . Ventus is the reason Sora holds a key-blade . Back when námine put sora to sleep , it must have possibly been a miscalculation , for rather taking the appearance of Sora , it took Ventus , since he is in Sora's heart.
By »»» Branxnod . Nobody of Brandon Roxas took on Ventus's appearance since Ventus was in Sora's heart.
Here is what happened: Ventus's heart went to Sora's and his body is now kept at Castle Oblivion. Sora had 3 hearts in him in KHI, his, Kairi's and Ventus's; which must have meant that 6 + 3 = 9 hearts got out while that happened, 6 from the Keyblade (Jasmine, Aurora, Cinderella, Alice, Belle and Snow White) the other 3 are Kairi, Sora and Ventus. However Kairi's went back into her, Sora's became the Heartless and Ventus's must've gone to Roxas in Twilight Town. Naminé was made in Twilight Town and then caught by Org XIII and put into Castle Oblivion. Roxas later merged with Sora at the end of KHII which means that he got back Ventus's heart.
Another thing though, apparently Nomura's original plan was for Ventus to "die" and be reborn as Sora, but for whatever reason he abondoned this idea for the current one in BBS. Evnyofdeath 03:14, February 1, 2011 (UTC)
Everybody is saying that Ventus's heart is inside Roxas the Nobody of Sora but there is a huge catch into this situation. Remember when Diz said to Roxas that he was part of the realm of darkness in KHII futhermore wasn't Ventus's Heart made of pure light since vanitas was extracted in Birth By Sleep and otherwise why would Ventus's heart seperate from sora if their hearts were Merged together. Just saying (KingdomHeartsSonic 10:14, August 11, 2012)