So Mordekaiser is supposed to be the master of metal

Why not rework him around this concept?

He has the heaviest armor in the game, yet ironically his armor stat is one of the lowest.

Idea:

Passive: -Mordekaiser has three metallic shard that he can control, he expands one of his shards whenever he casts an ability. -Those shards reinforce his armor when not in use. -Each metallic shards grants Mordekaiser 5-15 (+20%Bonus armor) bonus armor. -His Bonus armor is reduced by 30%. (So if he buys 100 bonus armor, he gets 70armor with not shards up, but 130 with all three shards up) -Casting a spell expands a shard, if the ability hits a champion, it absorbs some of their life energy and returns to Mordekaiser, refunding one of his shards. -If the shard doesn't hit a champion, it is only refunded when the ability comes back up. -If he does hit a champion with a spell, the shard returns to Mordekaiser after a small delay, granting him a shield. -"Ammunition" bar would be displayed below Morde's health bar to show how many shards he currently has up. -Visually, his armor would be heavily reinforced when he has three shards up, but with no shards up, his armor would show gaps under which can be seen Morde's spectre. -His abilities no longer cost him health, but would leave him more vulnerable instead, especially if he didnt hit a champion.

I'm not going to iterate his abilities, but i'm going to show how this reworked passive could be applied on his current kit.

Q: Refunds the shard if the third attack hits a champion.

W: Releasing the explosion would refund the shard.

E: Hitting at least one champion refunds a shard.

Pros: -No longer has health costs -Is really tanky with shards up

Cons: -Is vulnerable when he misses his abilities and has no shards up.