Can we just agree that Sion needs a buff?
I've been playing this champ since his rework almost religiously, he's taken me out of gold and into diamond during season five, I've played with both the "op" Sion spam E and now the "tickle me please" Sion. There's a lot of great memories with this champion, and I'll continue to play him. The problem with Sion currently isn't that his kit, whilst not exactly hard to dodge, just doesn't bring the necessary stats to team fight engagements or even the lane phase.
During lane phase, assuming you're like me and taking Dorans ring (You're forced to if you want sustain), you're hard countered by anyone with either %health or just a hard engagement where you can't utilize your kit properly (Riven, Fizz, Mao, Fiora, Garen's silence and spin to win, Darius and Illaoi whom just out damage you like no tomorrow, Quinn, Graves...) Your only hope of beating your lane is doing the E+Q combo, where you're usually taking a little above a quarter of health. This is assuming none of these champions have some sort dash or can't interrupt your Q charge during this time, even if you're able to get the Q off, the chances of you doing a full charge Q is almost nill, unless the person behind that keyboard is an armless hobo.
I'll try and do the math for everyone to show why Sion simply struggles in lane.
Q 60/120/180/240/300 (+1.8AD) (300% full charge) With a 1.8AD, and your end game Q should be doing, full charge with maybe 170 or so AD, depending on what you buy, you'll be doing 606 damage full charge. This, again, is assuming you're able to get that full charge. At the start of the game however, you're starting off with around 60-70 depending on your rune page. A full charge Q will do 168, again, this is assuming people are standing still for 2.25 seconds. Very unlikely unless you can ambush.
20/40/60/80/100 (+0.6*AD) (min charge) The minimum however, costs the same mana but has incredibly low damage with reduced range. 56 damage for just a quick spin at level 1. 45 mana from the start to do 56 damage. That's incredibly terrible. At max you're doing 202 damage roughly. Again, at level 18 for 202 damage is god awful.
Let's say I land an E on my opponent at level 4, I put 2 points in my Q, and I managed to half charge my Q, that's 200% roughly, assuming the charge AD% also rises, I'm guessing it's at 0.9AD. 80+0.9AD. Sion's basic AD is now at 69 so with simple math you get 142.1. That alone wouldn't even break a quarter of health on some if not most champions that play top lane. With E, then yes, it'll be about a quarter. Do that four more times perfectly without running out of mana, it's harder than it sounds.
What is the real problem with Sion's Q? It's the interruption. Instead of swinging down if he gets interrupted, he simply resets, with no mana refund and a 2 second cool down. That is a HUGE disadvantage especially against champions that have built in stuns such as Riven.
How to fix? Sion simply finishes his Q at whatever charge and swings downward, putting his CD to where it is originally, with the mana cost remaining the same. How would this improve his gameplay? Well it gives his opponents options. Do they risk for a quick stun and try and get that minimal damage and slow? Do they dash away? Do they just attempt to all in during his Q? Sion is meant to be played around. Being stunned constantly and being practically useless in team fights hurts him incredibly, since he actually is pretty reliant on his Q. I feel like with this change, it will make his kit a little bit healthier without putting him out of balance.
Next is his W.
The health stacking is great, I think it has a real balance. And his shield, while it is completely underpowered early on, with the health stacking it really shines through. The damage isn't bad at all. I think this is probably the most balanced thing about his kit.
Next is his E.
The main poke and why you should buy a Dorans ring if you're in lane. This ability alone is what made Riot bring they're nerf eyes onto him. Basically, shout at minions and try and skill shot for incredibly damage during the early stages of the game. However, this ability will later on tickle enemies, even if their armor is reduced by the ability.
While Riot was justified in nerfing this ability in the first place, the real problem it suffers from is that in order for this ability to be useful, it needs to be in lane with minions. The only thing I could think of without outright breaking Sion's E is to increase the range slightly, so he A. Isn't flat out losing lane against Fizz/Riven/Fiora/ETC. and B. If he misses his ult, which is usually half the time, he at least has a more reliable follow up. I think the damage and mana costs are fine, so I won't be going into the math portion.
Next his R.
I love and hate this ability. This ability gives Sion so much presence, and it puts the fear of God into other lanes if you're not on their minimap. It's pretty incredible if you can predict a gank and counter it with this, it just saves fights. Why I hate it? It's probably the hardest skill to land. Forget the Ashe arrow, forget Jinx's rocket, this is harder than hell to land.
I think this ability also hits like a pillow.
150/300/450 (+0.4*Bonus AD) knocks up enemies in a small area for 0.75 seconds
Level 6 - 150 flat damage. The chances of you having any items at level 6 that aren't damage orientated are slim to none. Level 11 - Lets say you bought a Titanic Hydra. You do a whopping (sarcasm) 314 damage at level 12. Level 16 - Lets do a Sterak and a Titanic this time. At level 16 your base AD is 116. 116*.25=29+35=64. 64*0.4=25.6. So basically you're doing 475.6 damage. Pretty garbage.
It's basically a quick peel that doesn't work.
300/600/900 (+0.8*Bonus AD) stun increases to 1.75 seconds. We'll use the same items.
Level 6 - 300 flat. No bonus AD Level 11 - 628. Level 16 - 64*.8=51.2. 951.2
What you're looking at is a very underwhelming ultimate in terms of damage, even landing this at full charge is considerably hard to do unless you're ganking from behind or the gankee is already stun locked.
The real problem here is the bonus AD. Sion typically doesn't build damage, or even bruiser builds. Preferring tank items that do the damage. (Sunfire, Thornmail.) So having that bonus AD ratio is completely useless, not to mention the ratios on it are just atrocious.
How to improve this? Turn the bonus AD into just AD and increase the ratio slightly. Especially at full charge. A Q that full charges has a 1.8 ratio. Why not just increase the full charge for the ultimate to be 1.5%? In most situations, considering how underwhelming this ability tends to be, it'll marginally improve Sions performance, not to mention it'll just feel pretty damn good to contribute something more. The 2nd problem is the stun duration. Sion is a big meaty tank, if he hits you, even at minimal range with his ultimate, it should feel like it. I'd say to increase the stun duration to a full second if hit by his ultimate immediately. It would simply just makes him a better peeler and a more viable option if things are incredibly close quarter.
Last things to mention as to why he underperforms.
His attack animations are just utter garbage. It's almost pointless to build any AD items on him unless it just helps his passive, which just defeats the purpose of him entirely, imo. Item's like Titanic or Sterak that you would think that would benefit him, just simply don't. I wouldn't know how to improve this honestly.
His AD ratios are just terrible, but he's a tank and that's understandable. That's really all I got. If anyone has something else they'd like to add, then please share. :D