Sejuani is my very favorite jungler and works great for just about every team comp. She has an amazing mix of cc, great engage and escape with her q, and can do some major play making once she has her ult. A good Sej player can often turn around an entire game with a well placed combo on the enemy team. I have around a 70% win rate on sej and have played well over a 100 games on her in ranked, and with no nerfs for her around the corner (it seems shes flying under the radar) she will remain a viable and good pick for awhile.

Pros:

- Great at initiating
- Groups well
- Works in most team comps
- Has good escape
- AOE clear
- Has innate tankiness with her passive
- Doesn't get hurt very much by cc especially slows
- Has tons of slows and decent amount of cc

Cons

- Doesn't work great against very mobile champs
- Weak jungle sustain
- Not great at dueling

Your gonna want to take a full clear as quick as possible since you have a weak early game you're liable to get invaded by the enemy jungler so you should always be prepped for that and have your smite up for both red and blue buff.

blue side
Start at krugs - start smite
place a ward in bush at red
go raptors
go to red - smite as last hit or close to it

check if mid is pushed up if it is attempt a gank
if not...
move up to wolves
be alert for potential top ccounter gank
take your blue
take gromp
gank either mid or top if possible
if not take scuttle
back


Its often not wise to gank bot till post 6

Your job in any team comp is to be a front line initiator or stay back and peel for your ADC. You are not an assassin if someone low breaks off from the fight and runs it is not your job to hunt them down, stay near enough to your carries that you can q or ult anything that jumps onto them. Only chase the enemy team if you're confident they have no way to jump to your back line. despite your AOE damage you can't 1v5 by yourself you need some damage dealers with you.
That being said if you initiate feel free to jump right at them and freeze as many of them as possible, get off a w and e and then fall back to protect your adc.

As long as your jungling with Sej the only real way to go is with Strength of the Ages , it provides a great health boost by mid game and will provide some of that extra sustain later with its 6% health return.
Bond of Stone is also a somewhat less viable choice providing a bit of damage reduction come team fight.
However any other keystone is just about useless in the jungle while playing Sej.

Sejuani's bread and butter combo is her Flash Arctic Assault Glacial Prison, This will take you into any lane by storm assuming your laner follows up this practically guarantees a kill