Welcome to the first guide I have ever made with probably my favorite champion that has been released since Wukong. With this guide you'll have some of the best slowing I've ever seen by a champion with . Also you'll be extremely difficult to kill.

Pros
-Super high health
-Lots of slowing
-Good escape tactics with Arctic Assault
-Good Farmer
-Northern Winds is very spammable with Shurelya's Reverie
-Still possible to get lots of kills
-Really good ganker with Arctic Assault and Glacial Prison

Cons
-Not a lot of armor or magic resist
-Very Focusable
-High Cost Items
-Not a ton of basic attack damage output

For your skills you want to get the damage output as high as you can as quickly as you can. For this reason you want to level up Northern Winds first. Now if you're wondering why I get Permafrost fully leveled before Arctic Assault here is my reasoning. With Permafrost you deal more and more damage at each level when you activate it. This move can act as a really good last hit on enemies that are just about to escape from you. The reason I don't get arctic assault is because the distance for the charge stays the same for every level plus the damage output upon each new level won't change that much from one to the next. It is certainly viable to switch how you level up these two skills or level them up evenly, but I have performed the best with this skill sequence.

For my masteries, I go 1-21-8. This is ensuring the tankiness that you need. In the defense tree make sure you master your heal and the basic armor and magic resist. Reducing/returning incoming damage from minions isn't necessary but it's definitely helpful. Also make sure you get any masteries that give you more health. In the utility tree I master mana and mana regen so you basically never have to worry about being low on mana. The last point is really up to you. I chose to get extra gold as it's always helpful but picking Runic affinity would be a good choice as well or a point in movement speed. It's really up to you there.

For my items, I start out with a Doran's Shield for the early health and health regen. Additionally pick up a Kindlegem and Boots of Speed for some cooldown reduction. Also grab a Regrowth pendant to keep the item build for Shurelya's Reverie going. Additionally at this point if you find yourself struggling for mana, take a Faerie Charm instead. Next pick up some Mercury Treads for extra magic resist and Shurelya's Reverie for good regen and cooldown reduction. For your mid-game, go for a Phage and Frozen Mallet. Using this your slowing capacity jumps to 50% per basic attack and 90% while using permafrost. This basically makes it impossible for anyone to escape you unless their name is Master Yi. From here on out you'll be picking items that get you more health to up the damage output of Northern Winds. For this purpose, pick up a Warmog's Armor. After the Warmog's you can choose between Rylai's Crystal Scepter and Atma's Impaler. Choose Atma's Impaler if you want even MORE slowing affect and choose the Atma's Impaler if you'd want some more damage output with your basic attacks. The main goal of all your items together is to give you the most amount of health possible to buff Northern Winds.

For my summoner spells I choose Heal and Ignite.

Reasoning:
I choose heal because it just increases your durability in lane. Additionally it helps your lane partner when they need it as well.
I choose Ignite for a few reasons. For one, it is always a good finishing tactic on enemies. A good way to make this tactic work is to have both permafrost and your basic attacks going and when they are ABOUT to escape, ignite them.

Other Viable options:

Flash: Flash is another way to add a extra escape or pursuit tactics. It could replace either heal or ignite but I would suggest replacing heal of the two. That way you will still have the extra damage from Ignite.

Teleport: Sejuani is not the fastest champion. While she does have Arctic Assault to give her a burst distance covered, grabbing teleport would give you even better presence in lane

Smite: Obviously If you would like to jungle as Sejuani, this would be the option to include. It gives the added damage you need against minions. Remember if you're jungling always use smite to kill the Golem, Lizard and Dragon.

The Runes basically speak for themselves by giving you the most health you can possibly get.
If you want to, you could get some armor or magic resist runes if you feel you are lacking in those areas. However, I have never had issues in this regard.

When you are laning early game, remember to spam your Northern Winds (w) a lot. It's your skill that provides the most damage output toward minions. Another very easy way to get lots of minion kills is to Arctic assault into a group of minions and then use northern winds as all of them will gain frost marks which increases the damage dealt to them. For early killing tactics I'll outline my main strategy.

1. Reach at least level 4
2. Inform your partner who you want to kill.
3. Go hide in the bushes
4. When the champ is in range, Arctic Assault toward them.
5. Immediately turn on Northern Winds and keep auto attacking
6. When they try to run away, turn on permafrost.
7. If they still are almost getting away, and you're level 6, use glacial prison. Otherwise, ignite them and possibly even turret dive them as Arctic Assault will most likely be out of cooldown by now which gives you a quick and easy escape tactic.
8. Revel in your victory

Additionally, this tactic works very well for ganking as well. Follow the same strategy as listed above. If you're looking for a change. Opening up the gank with Glacial Prison works very well.

When you get to the mid to late game, your role as the tank is going to become a lot more apparent. Some really good ways to play your role well in team fights are going to be listed below.

Initiate with Arctic Assault. This will add a frost debuff to every enemy hit which will give your team a really easy way to hunt down and kill their team quickly.

Don't be afraid to use your ultimate. It will stun every enemy in range of where it explodes which will give your team an even higher chance for unanswered damage output.

If enemies start to escape, get to them and use permafrost on them. That will almost ensure that they will die.


Also, once you get your Warmog's Armor, make sure you go and get lots of creep kills to get the buff going on it.

In conclusion, use this guide so that you can constantly harass the enemies with your slow and become a force to be reckoned with! Please post any thoughts and/or suggestions you have for the guide and post any successes you have with this guide!

Thanks everyone!