New Sejuani doesn't feel like a leader, is less healthy for the game, and is less fun to play.

So when are we reverting her? Because as far I can tell, that's 0 for 3 on the goals of the rework, making it a colossal failure. The stated goal of the rework was to make Sejuani feel like more of a leader, but in actual practice, it's almost always better for her to sit behind her melee allies and wait to stun people. In fact, the only way to chain stun someone as Sejuani is to let an ally proc her E stun for her and then ult because stunning someone with your ult prevents you from using E to stun them, but you can still stun someone with E and then stun them again with her ult. Hell, this lets you proc your passive %hp damage on that target twice, giving Sej far more burst than usual. It also encourages her to use her ult at close range while the rework was intended to encourage her to use it at long range. Not that using it at long range is worth it even with the extra benefits; the extra stun duration is usually wasted in the time it takes to reach the target and the AOE slow takes so long to start that most enemies will get out of the AOE well before the 80% slow kicks in.

But the absolute worst part about the Sejuani rework is that, in order to give her E (and by extension, her passive) this much power, they absolutely gutted the rest of her kit. Q lost nearly a third of it's base damage, lost .25 seconds of knockup time, and can only knock up a single target now. W's health ratio got completely gutted, it's mana cost enormously increased, it's base damage reduced, and is now effectively a single target spell against champions given how narrow the AOE actually is. It also got changed to physical damage for reasons I still can't figure out, which not only killed item diversity on her but also made her easier to itemize against and far weaker against tanks and bruisers since armor is far more common than MR. New Sejuani has decent burst and no dps, which is the exact opposite of what she had pre-rework. She went from one of the better dueling tanks thanks to her high dps to being unable to solo kill anyone unless miles ahead; I frequently lose 1v1s against adcs now where I could have 1v2ed the adc and supp before the rework with the same items.

And now onto her ult. It's shit. It's shit no matter how you decide to use it. At short range, it's a 1 second stun that does no damage. At max range, it's a 2 second stun that's usually wasted unless you ult while your allies initiate (nice leadership there Riot) and the AOE slow almost never hits anyone. It's honestly better to just flank and ult behind the enemy team as a zoning tool rather than ulting the enemy directly unless your allies initiate for you. Riot took one of the best ults in the game and turned it into one of the worst; I get that the old ult might have been too strong but the new one is terrible in both power and feel.

Riot turned Sejuani from a bruiser/tank hybrid into a tank/support hybrid, completely changing her playstyle, and not for the better. She's less independent and more team reliant than ever, and her new mechanics aren't even fun to use. Her ideal position in teamfights is no longer in the front, but in between her melee and ranged allies. She sits behind champs like Renekton/Irelia/Jax/etc. waiting for them to proc her stun while autoing the enemy frontline to stun them and bodyblocking skillshots aimed at her squishy backline. That's not a leader, that's a support. She's Braum 2.0 while managing to be less satisfying than him while also having less counterplay given how her E works. She's less fun for the person playing her, less fun for the people facing her, and utterly failed to make her feel like the leader, which was the supposed goal of the rework. They also loaded all of her kits power into the E while gutting all her other abilities, which is particularly ironic since "Her R being so strong limits what we can do with the rest of her kit" was also one of the stated justifications for her rework, except her new E drains even more power than her old ult did.

This rework is a failure in basically every aspect and she really wasn't that problematic before her rework; either change her back or do follow up work to fix her like you did with the Vel'koz rework. Perhaps remove the stun from her ult entirely and make the AOE start way faster and apply E stacks to enemies that stand in it; that change alone would give her more incentive to initiate herself rather than wait for allies to do so. Perhaps make it so her E stacks can only be started by her in exchange; it's kinda BS that allies can start stacking E for her anyway. How about changing her passive defensive stats to be weaker overall but be up more often: perhaps make it refresh every time she stuns an enemy or every time she procs her %hp passive damage. That would encourage her to actually stay in fights rather than blowing her passive and then running away like she does now. And please, dear god, give this champ some sustained damage back. I don't care if you have to gut the %hp damage on her passive in exchange, but alternating between dominating when you're stunning people and useless when you're not just feels terrible, especially when compared to AOE DPS machine she was before the rework.