Sion Fix(tl;dr at bot)
I think something that might fix Sion(maybe not entirely), is if he could move and/or rotate(like Varus, not Vel'Koz) during his Q(his smash). Because, if you've played as Sion, or against him with an appropriate champ, you'd know there's one thing he can't do above all else, duel. ADCs? not a huge problem, ranged in general? not too big a deal despite him being melee. Other melee champs? horrendously bad to fight. Lets look at the facts, Sion's shield doesn't do enough to protect him much(1-2 hits), and can't do dmg cause it pops before 2 seconds, his E does extremely low dmg in general, even if you hit someone with a minion/monster it's not too impressive(with the minion/monster hitting being impossible at melee range), his AAs are slow, not too weak, but not nearly enough to fight other AD champs, and this all leaves his Q as his only source of good dmg. But here's the thing, his Q is essentially worthless when not charged for at least the 1 second(extremely insignificant dmg at all lvls), now sure there are some cases where he might get the 1 sec off, like right after a slow and if he backs away a bit, but this is on enemies who don't have movement abilities(which, frankly, most AD champs have movement abilities).
To make the point as clear as possible here, look at Yasuo, Yasuo's dash and Sion's Q have the exact same CD at all lvls of their abilities(the mark that keeps Yasuo from dashing to the same target, in his case), with this not including that once off CD Sion still must charge for 1 sec minimum, what this means is that, if he should choose to do so, Yasuo can save his dash for literally every single time Sion starts his Q, and if used on Sion it'll place him neatly out of harms way every single time.(so basically Sion can not 1vs1 a decent Yasuo, period) This wouldn't be such a big deal if Sion had any way to make up for this weakness, but he doesn't.
tl;dr Sion needs a swivel chair for his Q
feels your pain, Sion)
His ult is easily side stepped even by champs with low mobility, and it has a global sound to alert opponents when he's using it.
, it's not because you were skilled, it's because your opponents were not.