I actually think the missing HP heals Illaoi and Darius have is a good direction for Bruiser design

I really hope riot takes a look at more of their less mobile beefcakes, some that didn't make the juggernaut patch and some that did. And I hope they consider adding missing %HP heals to their kits to allow them to stay in the thick of things like they've done with Darius and Illaoi (Morde too, but I'm focusing on these two for now).

This accomplished a few very important and significant things:

A) it removed their "wall of stats" gameplay. If Darius wants to stay alive and heal, he needs to land outer Qs. If Illaoi wants to heal, she needs to do damage with her tentacles. This requires strategic and mechanical gameplay for two champions that are a part of those class that is most notorious for being a walking wall of stats.

B) not only is this good for their teamfights, which makes them rewarding for playing well, it's healthy for lane phase as well. While Illaoi and Darius might be frustrating to face as melees, their lane phase power has very little to do with their heals. Darius is dangerous to fight in almost every situation unless you can avoid him getting stacks on you. Illaoi just spams to her hearts content and her hilariously low mana costs make doing so and missing spells very difficult to punish. But as I've stated, their heals are very healthy in lane, unlike champions in this past who beat up on minions and restore HP, these heals require champion interaction which is crucial.

I honestly hope you scrap the current garen disaster. I hope Nasus gets something similar, I hope even some of the more traditional melee carries or "light fighters" have an element of this incorporated into their kits as well because this is the best way you can give them relevance and gameplay at the same time without them being stat sticks. Not only is it more interesting; not only is it healthier gameplay; it allows you to give them really powerful potential and this makes their rewards actually satisfying where other melee bruisers or light fighters really fall short in that spectrum currently.