He is The Flash. Bypassing the reality revision of the Flashpoint event Wally West returned to this new reality after being lost in the Speedforce, we have learned that old foe Abrakadabra was responsible for sending him into the Force before the 'Flashpoint' effect hit and so Wally now finds himself in the new universe where his once wife Linda never met him and doesn't particularly like him.
Thanks to his Speedforce connection Wally was able to restore the memories of his friends The Titans and they too now remember their old lives. Aware that something out there is responsible for the revision after Flashpoint Wally, the Titans, Barry Allen, and Batman, are all independently beginning to search for answers to who and what caused the reality shift and where he/it might be at present...
Batman is investigating the Watchman angle, and how about current Supermake action in all of this?