I got good news for you:
I have official answers that no other site that reads engilsh has on it! I'm not guessing or putting two and two together I know! I KNOW! So don't say LIAR! Remember.... I KNOW!

The guy in the secret trailer that has the oathkeeper; his name is Sion! (or something spelt like that!)

How do you know?, you may ask I Have resources leading to the official japanese square soft (or square enix as you may say!) company!

Note: more information to come.