Sejuani bought the new champion, but was out here in mobafire build, had to create one.
I am Brazilian and I'm using google translator .-.
I'm new to create builds but I'll try.

Frost (Passive) - Sejuani's basic attacks apply Frost, reducing enemy Movement Speed by 10% for 3 seconds.
About: This is why Sejuani is powerful in ganks and team fights. If at any point the enemy has over extended themselves, without a speed boost or save from a teammate you can pretty much count your gold from the kill. Stops fleeing in it’s tracks. This is useful both offensively and as support. (Keep an enemy in range of the turret for 1 more shot? Why not.)


Arctic Assault - Sejuani charges forward to deal magic damage and apply Frost to enemies. Sejuani stops upon colliding with an enemy champion.
Range: 700
Cost: 70 / 80 / 90 / 100 / 110 mana
Magic Damage: 60 / 90 / 130 / 170 / 210 (+0.4 per ability power)
About: This is your opener, and it can be used creatively. Artic Assault applies your passive to all enemies it hits, which opens up for damage from both Northern Winds and Permafrost. You can powerfully snare an entire team with this, and in case thing go south it can be used to flee danger and even go over terrain.





Northern Winds - Sejuani summons an arctic storm around her which deals magic damage to nearby enemies every second. Damage is increased against enemies affected by Frost or Permafrost.
Cost: 40 mana
Cooldown: 10 second
Magic Damage per Second: 12 / 18 / 24 / 30 / 36 (+0.1 per ability power) (+1 / 1.25 / 1.5 / 1.75 / 2% of her maximum health)
About: This is similar to Shyvana but instead of increasing the duration it’s duration per hit, it deals increased damage /% of the champion’s health. This allows Sejunai to be a very effective counter-tank if coupled with a Madred’s Bloodrazor.



Permafrost - Sejuani converts Frost on nearby enemies to Permafrost, dealing magic damage and increasing the Movement Speed reduction dramatically.
Cost: 55 mana
Cooldown: 11 seconds
Magic Damage: 60 / 110 / 160 / 210 / 260 (+0.5 per ability power)
New Movement Speed Reduction: 30 / 40 / 50 / 60 / 70 %
About: Permafrost – exactly what makes Sejuani a great champ. It can turn your Artic Assault into a massive AoE slow, and deals respectable damage. When farming minions this is great alongside Northern Winds. A 70% slow to any champ will leave then extremely vulnerable for a gank – let alone being able to apply it to all 5 of the enemy champions.



Glacial Prison (Ultimate) - Sejuani throws her weapon, stunning the first enemy champion hit. Nearby enemies are stunned for a shorter duration. All targets take magic damage and are affected by Frost.
Cost: 100 mana
Range: 1150
Cooldown: 150 / 130 / 110 seconds
Magic Damage: 150 / 250 / 350 (+0.8 per ability power)

About: Similar to Ashe’s Ultimate, it fires a skill shot in the direction chosen to stun enemies.
But in this case – instead of insane range, this ultimate allows you to freeze multiple champions at once. With a respectable splash radius this can really lock up a team and make ganking a breeze and escape an option.

-> ->->(if necessary)