Alternate Identity

The world across the Gate is not, in fact, WWI Germany. The world across the Gate is 1996 in the Wizarding World, and a war is brewing. When Dante transports Ed to the other side of the Gate, Ed accidentally kills the body he inhabits, the Edward of that world. When he returns, the other Alphonse finds Ed and mistakes him for his brother, who has been missing for over a week.