There is no Kingdom Hearts 3. If you saw a YouTube video those are all fanmade, but if your referring to Kingdom Hearts Birth by Sleep you can play as Terra, Ventus(Ven), or Aquos. All of them are keyblade wielders in training(basically apprentices).
I think still Sora
She might be in Kingdom Hearts Birth by Sleep.Not Kingdom Hearts.
Roxas, or also known as Sora's Nobody. Kingdom Hearts 3 is titled as "358 / 2 Days" for the Nintendo DS.
Since you are referring to Kingdom Hearts 3 as Birth by Sleep yes but that isn't actually Roxas, that's a character named Ventus
Roxas is considered to be in 2 of the Kingdom Hearts games. He is the main character in the beginning of Kingdom Hearts 2 and then he is the character you play as in Story Mode in Kingdom Hearts 358/2 days.
Kingdom Hearts III is not in production yet. Tetsuya Nomura (Director and character designer for Kingdom Hearts) has said that he will start working on Kingdom Hearts III once the 'Final Fantasy XIII (13)' games are finished.
Kingdom Hearts 3 is Kingdom Hearts 358/2 days
sora is the main character in kingdom hearts. Goofy and Donald travel with him. He lives on destiny island.
Roxas appear in Kingdom Hearts video games. These can be bought for 3DS, PSP, Play Station 2 and 3. There are several games in the Kingdom Hearts series, such as Kingdom Hearts: Birth by Sleep and Kingdom Hearts: Chain of Memories.
No. He is not a playable character in Kingdom Hearts 2.
There is no Kingdom Hearts 3.
There is no Kingdom Hearts 3.