Darius has a heal now
why just why
his downfall was no sustain. So you fixed that problem, and ended up actually increasing his damage if he can pull off executing an enemy with his ult (Which isn't hard in teamfights) or stacking 5 stacks of his passive on a single target (Which is pretty damn hard to do).
So the way I'm seeing this, you moved him from a superb lane bully anti-carry into a teamfighting monster with very little lane bullying.
Really though, why?