Mordekaiser - No Longer A Caster
I have noticed, having had the conversation about 30 times in game (as they spam ping the items I buy until I hit someone), that it seems very few people noticed Morde's shift to being primarily an AD champion.
His Q (always has), his E, and even his Ultimate scale off of AD. Using a T-Force and Dark Harvest his damage output is immense. Still running a Gunblade, but with other items such as Black Cleaver and Stark's turn him into his old Raid Boss self.
Yes. The slow from Rylai's is nice, but ultimately that is all he now gains by diving into AP, and can be far more effective with a mallet.