Keeping tunnels spread out across the map will ensure you have choices when you want to cast Void Rush.
Cast Burrow before travelling around the map to take advantage of the increased Move Speed and the safety provided by Tremor Sense.
Tremor Sense can warn you of enemies closing in, and is particularly useful when entering enemy territory.
When Kayn is in terrain near you, you will get a visual warning on the edge of the terrain he's in.
Umbral Trespass requires Kayn to damage a target first. Try to dodge Blade's Reach to deny him a long range cast of Umbral Trespass.
Damage Kayn while he's in Shadow Step to shorten its duration, or apply hard crowd control (stun, charm, knockup, etc) to end Shadow Step immediately.
The stats shown on this page underscore some important Rek'Sai vs. Kayn counter statistics that may help us realize the distinctions between the pair. As an example, Rek'Sai’s KDA ratio ([kills + assists] / deaths) of NaN is greater than Kayn’s ratio of NaN, highlighting that Rek'Sai may be more central to his team's team fighting effectiveness than Kayn..
Rek'Sai often has a similar longest kill spree as his opponent does. Typically, he takes a similar amount of damage to Kayn. This is usually reflective of differing health capacities; however, it can also show that the champion with increased health has less mobility and thus is not able to escape further damage when poked or engaged.
Both League champions are great. Both have their strengths, weaknesses, and counters. In the game's current meta, Rek'Sai usually fairs equally well when trying to fight Kayn, with a 49.8% win rate. Therefore, Rek'Sai makes an ok counter for Kayn.
While Rek'Sai does have a lower winrate compared to Kayn, when on opposite teams, Rek'Sai also has a much lower learning curve that makes him a less difficult character to learn and master. You should be careful when picking Rek'Sai into Kayn.
Furthermore, Rek'Sai also has some amount of utility and CC, a similar amount to Kayn. This makes her just as valuable during team fights, especially when trying to counter champions with a lot of burst damage.
While there isn't a single best champion for every situation in League of Legends, in Rek'Sai vs Kayn matchups, Kayn is the better champ with a similar win rate, less champion complexity, and a similar amount of utility to help out your allied champions during teamfights.
Rek'Sai is a somewhat poor counter for Kayn. You will do well by focussing your actions on keeping up your gold income and destroying objectives. If you can do that, you should be able to stand on your own as Rek'Sai against Kayn.
If you would like to truly master Rek'Sai to counter Kayn during both the lane and mid / late game phases of League of Legends, you should keep reading to gather a few extra lessons on this matchup. If you mind the build and tips displayed above, you should increase your win rate by a lot and be closer to League of Legends pro players.
Rek'Sai most often racks up a similar amount of CS relative to Kayn. Champs who on average don't earn many minion kills often don't require much CS to be valuable teammates, such as sup champs. These kinds of champions are capable of scaling properly off of their abilities and first items alone. Yet, champs with large amounts of CS, such as hyper-carries, often have to have several high cost items to be effective. In either case, try to do better than the values reported here to do well.
The best items to prioritize in your Rek'Sai versus Kayn build include Black Cleaver, Youmuu's Ghostblade, and Titanic Hydra. When Rek'Sai included at least these three items in his build, he did much better when facing Kayn than with most other commonly used counter builds. In fact, Rek'Sai had an average winrate of 49.8% when playing against Kayn with this build.
To have the best chance of defeating Kayn as Rek'Sai, you should equip the Conqueror, Triumph, Legend: Alacrity, Coup de Grace, Magical Footwear, and Cosmic Insight runes from the Precision and Inspiration rune sets. Out of all the runes that we analyzed for Rek'Sai vs Kayn counter picks, this sequence of runes yielded the greatest win rate. Notably, these runes gave a 49.8% winrate overall.
If you would like to view Rek'Sai x Kayn tips and matchup stats and build suggestions for a an individual rank, feel free to choose one from the selection menu provided above. If viewing for the first time, the statistics and build suggestions given are calculated using every match with data with these champs.