Sejuani Runes explained
There's one set of runes for Sejuani on patch
11.12
that is the clear favorite for LoL players and pros alike. The best Sejuani Runes on the position 
Jungle are Resolve as the primary path and
Precision as the secondary path with a pick rate of 81%. Besides runes you should take a look on Sejuani Build and if you are interested in pro matches take a look at Sejuani Probuilds. If you want to discuss
Sejuani then you should visit the champion subreddit.
Primary path on Sejuani
Resolve empowers the survivability of Sejuani and increases the tankiness. Most of high elo players – and our LoL pros in the the major regions – have agreed that
Aftershock is the best keystone rune to run on
Sejuani. This keystone rune bulks you up, increasing both armour and magic resistance, once you immobilized a champion.
Aftershock synergises both with the sheer amount of crowd control Sejuani possesses and the need to be tanky as soon as you engage. This is usually followed up by taking
Font of Life,
Bone Plating and
Unflinching.
Font of Life provides your teammates with more sustain by healing them whenever they attack a champion whose movement you've recently impaired.
Bone Plating make Sejuani overall tankier, by decreasing the amount of poke damage in the early game.
Unflinching inceases Sejuani tenacity based on your missing health.
Secondary path on Sejuani
When it comes to your secondary path, most
Sejuani players prefer to go with
Precision.
Precision improves attack and sustained damage on Sejuani troughout the match. On the
Precision path, the best runes for Sejuani are
Triumph and
Legend: Alacrity.
Triumph restores on Sejuani a part of missing health and award bonus gold, if a champion is killed.
Legend: Alacrity grants additional attack speed to Sejuani.