Who is he?
What is he?
When is he?
For me, he's a man shrouded in mysteries. All I know is that he must be an Uchiha a. Apart from that, I can only speculate who he really is. Is he obito? Is he Madara's brother? Is he Sasuke's father?
Well, who know? It seems we'll only find out if we keep watching the series.
Still, I somehow hope people have an idea:)