Hi, I mained Sejuani back in season 5 when I started playing this game, because I was seeing it by the pro teams and I liked her. So many patches later, every other meta jungler has been buffed, nerfed, and buffed again, and Sejuani only received a very tiny buff to her W damage early on.
With the jungle changes (Red, blue, frog being solos), her W clear is just not fast enough, she is very susceptible to counter jungling and solo killed and 1v1s, and her ganks might be good, but there are other junglers who gank so much better. She is still decent as a teamfighter, but even as a tank, she doesn't get a lot of tank stats, apart from her underwhelming passive, whereas other tanks do (Maokai has his ulti and his healing passive, Poppy has her W and shields). Sejuani just has some trivial Armor bonus.
I think we have reached the point where Sejuani's identity isn't known. She does have a great ulti, and a decent slow, but that's about it. She doesn't get naturally tanky, doesn't have great scalings, very slow jungle clear and weak 1v1 potential. Like, what is her role now? Being a tank? There are so many other tanks out there who are naturally better. Applying crowd control? There are other champions with equally as good or even better (Malphite, Nautilus etc). Early pressure? Non-existent.
What is she supposed to be and more importantly, what does she have, apart from ther poro skin, that makes her special over other picks? And the problem here is that I don't really know what can be done to bring her up a bit. Boosting her damage so that her clear is slightly faster? Still won't be as fast as other meta junglers. Increase her CC duration /strength? That would make her broken. Probably, reworking her passive into something more important would be a way to go, something like making her more efficiently tanky when hitting someone with CC or w/e.
I'm open to ideas of getting her back in line, or if you think she feels underwhelming right now.