i do not even know what to say.
Other than Skarner, yeah, but Skarner's problems go deeper than mana on his Q.
Hecarim is a jungler with amazing gang, can snowball, tanky, and AOE CC. Oh right, he is also impossible to chase down without hard cc, and ult also double as a free escape. Now he can hog over small cliff like nidalee. At least with rammus you can escape the gang by standing behind a minion.
The mana nerf does nothing to his early game presence since he will be running around with blue buff.
If to want to get really reductive about champions and just put out a list of their strengths without showing what counter play they have, sure we can do that.
Eve is a highly mobile and really versatile AP mage who has an AoE %HP nuke that also gives her a shield, she has mass mana regen, extremely flexible build path, a slow, is an amazing ganker, does a tonne of damage, has an attack speed boost, a movement speed boost and, oh yeah, she's invisible half the time. Ans she's a waifu.
Udyr is a highly mobile tanky utility jungler who has one of the most flexible build and ability paths in the game, he has a passive ability which stuns and mini dashes to who he targets, has great AoE clear, has amazing persistent damage, a shield, flat health steal, multiple speed boosts, great chase potential, high damage and he's getting an ultimate skin.
Breaking it down like that would make Rengar or Elise the best champion in the game.
Hecarim has counter play. Hard cc, deep wards, map awareness (god forbid), snowballs in both ways so if you shut him down he has a really hard time coming back because he's so item dependant, and he can be kited by things like blue ezreal or whatever.
A champion is allowed to be strong. He's a good solo queue jungler, although outside of China he's been shown to be a non-desirable competitive pick, and even in high ELO games has stopped being pick or ban generally.
Not to mention you have champions like Jarvan who had one round of nerfs who's still tearing it up in solo q and competitive and he's "fine". Or Zac who offers so much utility that he's a way higher priority ban than Hecarim. Or Elise, who despite being nerfed, is still stronger and has more going on in her kit.
Just because a champion is good in a certain environment doesn't mean you have to nuke them until they're weak, unless they're terribly designed like old Eve or like Yorick.
