Nerf Sivir. She's become S tier and has no counter play.

She's the pre nerf Riven of botlane.

-Spell shield that avoids all cc, can be baited, but not easily, nullifying many support counters. -Q damage and auto attack bounces has huge early game damage advantages and is oppressive and safe as fuck when combined with spell shield. -Scaling is good enough to be viable well into the 30 min mark. -Ult buffs whole team. -Passive + the move speed of boots is enough to give her a major kiting and run down advantage, with little counter play thanks to her spell shield, ult, and front loaded damage. -Q is lessened using minions as cover, however the hit box, range, and damage even after reductions is still substantial and offers little counter play.

Where is she supposed to be weak? How is this balanced?

It can be argued that while Ezreal, Draven, and Jinx are all currently S tier picks, these 3 all have exploitable weaknesses;

Ezreal falls off late, is all skill shots and relies on casting to do his damage. He has predictable power spikes that you can play around and exploit.

Draven is easier to catch and does not have any spell shield, being forced to use an item slot on Mercurial Scimitar or GA. combined with his shorter range is very much able to be played around. Albeit still scary.

Jinx is a hyper carry who requires a team in front of her and for her cc to connect. Get caught and yur fucked as Jinx. She relies on her enemy not being able to touch her.