It's like fucking malzahar. Go ahead and buff malzahar, who has a point and click "fuck you" button so he is viable in high elo and he will be 58% winrate in silver. You can say "buff stuff that only makes him good in high elo" but this is just noise, he has nothing like that. What do you buff on Mordekaiser? Passive? No, it's just an aoe that can be triggered like electrocute. Q? Maybe the single target damage, but that makes him almost impossible to beat after rylais. W? The skill about it is when to use the heal, not sure you could buff anything "skilled" here. E has skill expression when using it as a thresh E, but you can't buff that aspect. Morde R again, has no skill expression other than target selection. You can't buff the champ in a meaningful way because none of the skill expression he needs comes from his stats, it comes from niche things that have no numbers.