The Darius rework in a nutshell:

Lets nerf his Q. It'll do substantially less damage if you hit with the hilt and not proc a bleed. It'll also have a 0.75 second delay that doesn't allow it to go on cooldown until it's over, giving it a 0.75 second CD increase that can't be reduced with CDR. Also, even if you hit with the blade, lets reduce that damage by 60 too.

Nerf his passive damage, and change it to physical so it does even less damage.

Nerf his W damage too. And increased the cooldown. And you need to max it to reduce the cooldown, rather than just get that for free by stacking bleeds. Also we reduced the slow duration.

Nerf the bug on his E that was letting him be even somewhat viable. Give it an insignificant cast time reduction that doesn't even begin to make up for how low range it is now.

Nerf his ult unless you have 5 bleeds.

Remove his attack speed slow, and give him a HUGE WHOPPING... 9 armor and 100 HP to make up for it. Except dead man's and all other armor items got nerfed anyway so that's pretty insignificant.

BUT IT'S OKAY... we've nerfed every single ability because once he gets 5 bleed stacks he gets more damage!

We've also massively nerfed his attack speed so he can never get 5 bleed stacks. Get fucked Darius.