Well, I’ve been digging Mundo lately and I find his kit very diverse. But a thing and have noticed is his passive being half Garen’s passive, just all the time. And after rank 8 you just don't feel the healing from 1.5% of his maximum health.
I did some experimenting in the sandbox by going 5 warmogs and one spirit visage too maximize the healing I get. I ended up with 90.7 health regen per second, pretty good right? Except it isn't because I had 6,3k health, lvl. 18 and stacked overgrowth a lot, and I feel like that 90,3 regen ain't that much suddenly when you think about it.
So I just wish that his passive would scale, maybe over level or maybe do it like Kayle’s passive where it comes in increments. Or maybe get some more of his lore in by giving his passive a % spellvamp/lifesteal based on Mundo’s missing health or something like that.
If you have anything to add, please comment your opinions and thoughts on Mundo's passive and maybe also some ideas of how to make it better