So I started play Yorick some, and wow
This guy is really sleeper OP.
By building manamune, juggernaut items, and hitting 40% CDR, you can virtually almost always have ghouls up to keep your damage reduction passive up. This coupled with high DPS (I went Triforce because it seems wonderful on him), you can surprisingly destroy enemies. His sustain is wonderful, the damage reduction passive makes you tanky, you have a massive movespeed steriod, AND a slow. I mean wow. And your ult is a mini Sion passive!
The only odd thing is his ult. It's just... strange. You use it, come back to life, which is neat, only to die anyways.
I still love Mordekiaser more, but the DPS on Yorick and how tanky he can be in duels is very impressive. I have been surprised in every one of the few games I have played him. It's a wonder Noone plays him.
I hope the eventual rework doesn't cut out the damage reduction passive. It's pretty great.