Mordekaiser Rework suggestion (+some lore)
Years ago, people who play Mordekaiser were crushed to hear that he was being changed from a burst mage to a bruiser, and Riot didn't even have the decency to do a full rework, only changed his Q and nerfed it to the ground immediately after.
Now, he's no longer the bottom-lane replacement they wanted. He's hardly even a top laner, and he can't hold a candle to anyone at mid.
So here's my suggestion for an actual rework. Slightly adjusted from my suggestion three years ago.
Passive: Basically the same, as I think it's core to his identity. But it should be a percent of the shield per enemy hit, like the healing of the other juggernauts. Tying it to his damage dealt is directly opposed to the normal attributes of the class, which is supposed to be able to build one core damage item and the rest defense.
Q: Completely revert this ability. Obviously, change the visual. But it was infinitely more fun when it wasn't a three-hit thing.
W: Keep the visual, but instead of cast on an ally, it should be thrown onto an enemy. Apply nearsight, and keep the movespeed towards the target+AoE damage if you're in range. With the suggested change to his passive, I feel the heal from this could be removed.
E: A swing with his mace in a cone in front of him, with basically the same area as current but displace enemies for 0.15s in the direction of the swing.
R: Arguably the defining aspect of the champion, it fell short with the removal of the guaranteed bonus AD and Mord's ability to burst a target.
I think he should summon a ghostly Demacian* knight as a pet to assist him, the ghost would have his current W (as if it were cast on an ally) and a weakened version of his current Q as a three-hit passive, with a sword instead of a mace.
Dragon Force (the name of the part of the ability that allows him to control the dragon's ghost) should be kept as is... with a slight adjustment: the model would have his ghostly ally riding it.
Now, here's where lore comes in. I think it should be adjusted to specifically state that he fought against Demacian enemies... due to one part of Galio's champion insight:
"With this aura in place, few could throw the Knights from their mounts, the legendary ebony wyverns. Thus, the sculptor Durand specifically designed Galio to look like a chimeric combination of knights and wyverns, to signify the unity of Demacian warrior and beast."
The spirit summoned by Mordekaiser could be that of one of these wyvern-riding knights, and when he gets the dragon for Dragon Force, he commands that knight to ride atop the dragon.