Unpopular opinion: Morde should get ghosts back in his kit
The ghosts in Morde's old kit were fun and enslaving the dragon was so unique to the game. Sure they were strong, but it gave Morde a lot of macro power and added complexity to what some would call a "braindead" champ. New Morde's kit seems really vanilla and seems like Riot just wanted to play safe when making him. After Morde's numbers are nerfed down to a reasonable level, I can see him going back to being a low pickrate champ due to how telegraphed his entire kit is, and how immobile he is.
While his ult can be fun, the whole idea of death realm isn't all that interesting considering that there is virtually no reward for winning the fight, and later in the game it's hard to kill enemy champs outside the support since they will have zhonyas, Qss, or will have outscaled you.
I think instead of taking stats out of the death realm, Morde should get the enemy champion's ghost. This would make him closer to his old self and would bring that cool mechanic back in the game.