Darius heal modification: Half immediate, half over time
Darius' ability to potentially burst-heal himself for 1k health is kinda absurd. Within a brief instant, he can get a full Warmog's worth of health to absorb another volley of burst attacks, making him super hard to kill nowadays once he gets close (not too hard, in all honesty).
I think that to make this a little less nasty, the heal should be changed up to be more like Mordekaiser's Children of the Grave healing (or Trundle's Subjugate). Make it so that it heals half its amount immediately, and half over a short duration. This way, he'd only heal about 400-500 instantly (instead of 800-1000), and you could still burst him before the rest of the healing kicks in.
can be used to shut him down pretty efficiently. Obviously you don't want to go in melee range against a Darius... so if you can lock him down from a distance there's nothing he can really do.
+
. Works for all the juggernauts.