Midlane Mordekaiser
People say he's garbage now but in my own personal experience he's not much worse than he was. Not having a W sucks but really Mordekaiser only had 2 real abilities before the rework, his W just gave you a tiny bit of resistances and the damage was negligible (and against most mids completely irrelevant because you'd rarely be close enough for long enough to make it relevant) unless you maxed W first but if you maxed W first you had no kill pressure in lane.
Mordekaiser's E got a base damage nerf but it scales with your total AD now, meaning it does just as much damage as before at level 1 and more damage than before once you pick up gunblade. His early game shield got a buff, especially his shield generation with the 15% increase on his E.
I still max E on him. It's way stronger in lane and his Q does enough damage at level 1 that you don't really need to put points into it. Unless you're in bot lane, ranking up your Q is just gimping your laning phase. E is all of your waveclear, all of your poke, and your only tool for participating in short trades. Mordekaiser has more kill pressure with flash now that he has his new Q. You can 100-0 almost any mid in the game with autoing a minion twice, flash AA > E > Ult > Ignite. Other than that silly interaction, his Q is worse in every single way than before, and he doesn't have much burst potential at all without minions around and his flash up, unlike old Morde's Q which hit pretty hard no matter where you were. The only time you're going to be getting a kill with his Q outside of minion waves is when the enemy is dumb and walks into melee range and stays there until you get all 3 Q's off.
Morde already had reasons to buy hybrid items like Gunblade before the rework, but now that they also added an AD ratio to his E, pseudo-attack-speed scaling on his Q, and health + pseudo-resistance scaling on his shield, he can build pretty much whatever he wants, any item in the game that doesn't involve mana, and be effective. You have access to literally the entire item pool, which gives you great diversity in your build options.
**For example, he is the only champion I know of that can build both a Zhonya's and a Merc Scimmy and not suffer for it.**
I can't stress enough how strong this is, to be able to build any item in the game. It gives him great adaptability.
I feel like he scales much better with CDR now that he has lower cooldowns and higher durations on his abilities. With 40% CDR, you can keep someone permanently ghosted as long as you keep killing them often enough. At max CDR his E has a 3 second cooldown, which is also pretty crazy because it generates way more shielding than before.
Overall I honestly preferred the pre-rework Morde, I greatly preferred his old Q and I miss his outrageous waveclear, but this new Morde isn't nearly as bad as people make him out to be. I'm actually greatly confused as to why his winrate tanked so much in solo lanes. I was extremely pessimistic when I heard that they were going to change him into a botlane carry, but I took it as a sign of things to come, I expected more changes but it turns out he is mostly unchanged from when he first went on the PBE. If I had my choice I would revert his rework, but I'm not completely upset with the way he is now. I 100% agree he should get his W back in solo lanes, but if he doesn't it's not that big of a deal when you think about how weak his W already was previously it doesn't make too big of a difference to not have it, it's still useful in teamfights and it's not the end of the world for Morde to not have it in lane. I also would be totally OK if they just removed the dragon passive completely, it feels extremely gimmicky and I absolutely loathe how it prevents you from using your ult. I get it, it gives me a lot of lane pressure while it's alive, but I would honestly rather be able to use my ult than to have a dragon.
The one thing I am worried about, is his duo lane. I don't care about it nor do I have any interest in taking Morde bottom lane, but I feel like he's going to receive many nerfs to tone him down, which will end up making him irrelevant once again in the bottom lane, and as consequence completely gutting his solo lane. Because of the way he works, if he's not overbearing in bottom lane, nobody will play him bottom lane. Riot claims they have buffs for solo lane Morde, but I don't see how they can possibly do that while simultaneously nerfing his duo lane, and apparently Riot doesn't either because they claim it's unlikely he will ever return to a 50% win rate in solo lanes. I feel like it's only a matter of time before Mordekaiser is completely irrelevant in all roles.