KM Drago is used in Disaster Dragon decks to hurt the meta. You obviously don't use REDMD when KM Drago is out. Even if it dies in the end phase since you don't have a dragon-type to reveal (which shouldn't be the case), you can just revive it next turn with REDMD.
Your deck is looking pretty good, although I might not run Oppression in here. I'd probably lose a LaDD and Oppression for Call of the Haunted and a 3rd Wyvern.