Who do I have to make passionate love on to get a Sion buff?
No seriously. I'll do it. I swear. Sion is a ton of fun. A ton. But his power level is WAY too low.
Like, I get it. His Passive is strong. His ulti - pretty great utility wise. But for a massive behemoth carrying a gigantic axe/hammer, I feel like I'm not doing anything - even when I go full out offensive. And his health stacking is potentially limitless - although short of a shield, his kit doesn't really fit that of a tank (he's got the stuns, but they aren't exactly reliable). As a damage dealer, he feels lacking and incredibly punishing for little to no reward. As a tank, you don't offer the consistent utility for a team, nor do you really make the most out of your passive.
And I mean, he's punishing as hell to play now too. Not only is your damage low, but your hammer wind up is one of the most telegraphed mechanics in the game, and it's piss easy to dodge. Especially if you're against someone who can somehow disrupt you, which just causes the effect to fizzle.
And his Ulti is a great utility thing, but it's WAY too punishing for its benefits. It's a less powerful, less reliable version of Destiny or Skyfall that is not only largely telegraphed to anyone with their audio on*, but it's interrupted by terrain. And the stun utility is great - the damage, not so much. Logic should dictate that if our moves are so easy to telegraph and dodge, they should be extremely punishing to people who don't get out of the way, and extremely rewarding for anyone who does hit it.