What about making Mordekaiser's shield TEND TO 50% (decay if above, generate if below)

Mordekaiser is heavily snowbally since you have to deal damage to have the tankiness too. A solution to this could be to have him get some tankiness not dependingly on his damage. This is a net buff and it wouldn't hurt given how weak he is atm, but if he became too strong the damage -> shield conversion could be reduced.

Afraid of it being too oppressive in solo lanes? Have the generation go up to 4x when 2 or more enemies are nearby (within 2000 units?) for more than 10 seconds, and make it low for the 1v1 case.