my theory on dr.Alchemy: What if Dr.Alchemy was from earth 3 and was Bought to earth 1 by one of Savitar follows so that he can get barry to the speed force so that Savitar can escape and Dr.Alchemy is the doppelganger of Julian Albert who's the archenemies of Jay Garrick/Flash and Barry Allen/The flash. later in Season where we see Dr.Alchmey kidnapping Earth 1 Julian Albert where Dr.Alchemy takes of his mask and reveal his face to Julian Albert where we see Him Getting freak out when he see that someone looks like him