i primarily play on another account. i played only 10 ranked games on this account in season 2, and as you saw half of them were sejuani.
tbh though, i've only recently felt confident enough with her to use her as my primary in rankedi had to play a ton of normals with her firstbut, yeah, i intend to stay with her for a long while.
Seju has great input in teamfights late game as long as team has confidence in you and folows your initiation.HOWEVER, her early game presence as a jungler is very low.
She can ASSIST lanes by ganking, but her damage is very low, and if lane isnt joining gank or very far behind sejuani isnt able to do much.
This has a very negative psychological effect on team, so in mi/ late game when you become actiolly effective in solo queue teams dont folow your initiations and waste your whole potential.
This sums up in sejuani being bad pick. As you see from my number of games with her i like her alot, but her low damage makes her bad pick for solo q jungler.