Lay Waste is very strong at farming minions and harassing enemy champions.
Ask your allies to help point out when you should use Requiem to get kills in different lanes.
Kai'Sa is very vulnerable to getting outranged by mages and long range carries.
Make sure to place wards in your blind spots so you can see Kai'Sa coming.
Kai'Sa is very good at picking off isolated enemies. Stick together against her.
The stats shown on this page show some influential Karthus vs. Kai'Sa counter statistics that may help us realize the distinctions between this pair of champions. As an example, Karthus’s KDA ratio ([kills + assists] / deaths) of NaN is better than Kai'Sa’s KDA ratio of NaN, highlighting that Karthus may be more central to his team's team fighting capability than Kai'Sa..
Karthus often has a similar longest kill spree as his opponent does. Commonly, he takes more damage than Kai'Sa. This typically indicates different amounts of tankyness, yet it can also indicate that the one champ has less mobility and thus is unable to escape additional harm when poked or engaged.
Both League of Legends champs are great champions. Both champs have their strengths, weaknesses, and counters. In League's current meta, Karthus usually fairs equally well when trying to fight Kai'Sa, with a 50.6% win rate. Therefore, Karthus makes an ok counter for Kai'Sa.
While Karthus does have a higher win rate compared to Kai'Sa, when on opposite teams, Karthus also has a greater difficulty level that makes him a more time consuming character to learn. You still need to be cautious when picking Karthus into Kai'Saas his relative depth means you may not be able to unleash his full potential without a significant amount of practice beforehand.
Additionally, Karthus also has some amount of CC and other utility, a similar amount to Kai'Sa. This often makes her just as valuable during teamfights, especially when fighting champions with a lot of burst damage.
While there is not a single best champion for every situation in League of Legends, in Karthus vs Kai'Sa matchups, Karthus is the better champion with a similar win rate, more champion depth, and a similar amount of utility to help out your allied champions during teamfights.
Karthus is a decent counter for Kai'Sa. Focus your strategy on maximizing your CS and destroying objectives. If you can do that, you should be able to stand on your own as Karthus against Kai'Sa.
If you would like to truly master Karthus to counter Kai'Sa during both the early game and mid / late game phases of League of Legends, you should continue reading to gather a few extra lessons on this matchup. If you mind the build and tips presented here, you will increase your win rate significantly and be that much closer to League of Legends pro players.
Karthus most often picks up less CS compared to Kai'Sa. Champions who typically don't take many minion kills often don't have to have much CS to be valuable teammates, such as sup champs. These kinds of champions are capable of scaling well off of their skills, stats, and first items alone. Yet, champions with large amounts of CS, such as hyper-carries, usually have to have several high cost items to be effective. In either situation, try to do better than the numbers shown on this page to do well.
The best items to use in your Karthus versus Kai'Sa build include Rabadon's Deathcap, Malignance, and Void Staff. When Karthus bought at least these three items in his build, he did much better when facing Kai'Sa than with many other commonly used item sets. In fact, Karthus boasted an average win rate of 50.6% when countering Kai'Sa with this counter build.
To have the greatest probability of defeating Kai'Sa as Karthus, Karthus players should take the Dark Harvest, Cheap Shot, Eyeball Collection, Ultimate Hunter, Presence of Mind, and Last Stand runes from the Domination and Precision rune sets. Out of all the rune combinations that we analyzed for Karthus vs Kai'Sa counters, this set of runes resulted in the greatest win rate. Notably, these runes gave a 50.6% win rate overall.
If you would like to view Karthus vs Kai'Sa tips and counter builds for a a particular division, feel free to select one from the selection menu shown above. If viewing for the first time, the statistics and strategies given are calculated using every round finished with both champions.