Melee allies can stack Frost for your Permafrost, keep an eye on who they are attacking.
Save Glacial Prison for encounters where you have teammates present to take advantage of it.
Use Arctic Assault to escape bad situations, interupt channeled spells or chase runners.
The stat comparisons shown here clarify some strategic Sejuani versus Vex counter statistics that can help you appreciate the differences between the pair. Sejuani’s KDA ratio ([kills + assists] / deaths) of NaN is better than Vex’s KDA ratio of NaN, showing that Sejuani may be more central to her team's team fighting effectiveness than Vex..
Sejuani typically has a slightly smaller longest kill spree than her enemy does. Commonly, she takes more damage than Vex. This often reflects differing health capacities; however, it can also imply that the champ with more health has less mobility and thus is not able to flee from additional damage when engaged or poked.
Both LoL champions are great. Both have their pros and cons. In the game's current meta, Sejuani usually loses when taking on Vex, with a 45.6% win rate. Therefore, Sejuani makes a bad counter to Vex.
While Sejuani does have a much lower win rate compared to Vex, when they face off with one another, Sejuani also has a much greater difficulty level that makes her a more difficult character to learn. You should be very concerned when picking Sejuani into Vex.
Furthermore, Sejuani has a good amount of CC and other utility, a similar amount to Vex. This makes her just as valuable during teamfights, especially when facing champions with a lot of burst damage.
While there isn't a single best champion in League of Legends, in Sejuani vs Vex matchups, Vex is the better champ with a much lower win rate, more champion depth, and a similar amount of utility to help out your allied champions during teamfights.
Sejuani is a trash counter for Vex. Focus your actions on increasing your CS and clearing objectives. If you do that, you should be able to stand on your own as Sejuani against Vex.
If you would like to truly master Sejuani to counter Vex during both the laning and mid / late game phases of League of Legends, you should continue reading to learn a few extra lessons on this matchup. If you listen to the build and tips displayed here, you will increase your win rate significantly and be that much closer to League of Legends pro players.
Sejuani on average picks up a lot less CS as Vex. Champs who typically don't acquire many minion kills typically don't need much CS to be valuable teammates, such as supports. They are able to scale well off of their skills, stats, and first items alone. Yet, champions with a lot of CS, such as hyper-carries, typically have to have many items to be effective. In either case, try to exceed the numbers shown on this page to do well.
The best items to have in your Sejuani versus Vex build consist of Sunfire Aegis, Thornmail, and Jak'Sho, The Protean. When Sejuani included at least these three items in her build, she did significantly better against Vex than with most other common item sets. In fact, Sejuani boasted an average winrate of 45.6% when countering Vex with these items in her kit.
To have the highest chance of crushing Vex as Sejuani, you should take the Aftershock, Font of Life, Conditioning, Overgrowth, Legend: Alacrity, and Triumph runes from the Resolve and Precision rune sets. Out of all the rune builds players picked for Sejuani vs Vex clashes, this composite of runes yielded the highest win rate. Moreover, these runes provided a 45.6% winrate overall.
By default, tips, statistics, and builds on how to beat Vex as Sejuani are presented for all ranked divisions combined. To narrow the stats and builds to a particular skill level, you may use the selection menu earlier in the counter matchup guide.