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.
The stats provided here underscore several important Karthus versus Sett counter stats that may help you interpret the differences and similarities between this set of champions. Karthus’s KDA ratio ([kills + assists] / deaths) of NaN is better than Sett’s ratio of NaN, indicating that Karthus may be more central to his team's team fighting potential than Sett. This observation is in large part fueled by the differences in assists.
Karthus often has a similar longest kill spree as his enemy does. Commonly, he takes less damage than Sett. This often reflects different amounts of tankyness, but it can also imply that the one champ has less agility and thus is unable to kite away from further damage when poked or engaged.
Both LoL champs are great champions. Both have their pros and cons. In League's current meta, Karthus usually loses when playing against Sett, with a 46.9% win rate. Thus, Karthus makes a poor counter for Sett.
While Karthus does have a lower winrate compared to Sett, when facing one another, Karthus also has a much greater difficulty level that makes him a more difficult champ to pick up and master. You should be very concerned when picking Karthus into Settas his relative depth means you may not be able to reach his full potential without a significant amount of practice beforehand.
Furthermore, Karthus has some amount of CC and other utility, a similar amount to Sett. This makes her just as valuable during teamfights, especially when fighting champions with a lot of burst damage.
While there isn't one best champion overall in League of Legends, in Karthus vs Sett matchups, Sett is the better champ with a much lower win rate, more champion depth, and a similar amount of utility to help out your team members during late stage team fights.
Karthus is a terribly counter for Sett. Make sure you focus your tactics on maximizing your gold and cs and clearing objectives. If you can do that, you should do very well as Karthus against Sett.
To truly master Karthus in order to counter Sett during both the laning and mid / late game phases of League of Legends, you should keep reading to gather a few extra tips and tricks for this matchup. If you mind the build and tips displayed above, you should grow your win rate by a lot and be that much closer to League of Legends pro players.
Karthus often gets less CS as Sett. Champs who typically don't get much CS usualy don't require much CS to be valuable teammates, such as supports. They are capable of scaling properly off of their skills, stats, and first items alone. Yet, champions with large amounts of CS, such as hyper-carries, typically have to have several high cost items to be effective. In either case, try to exceed the values displayed here to do well.
The ideal items to have in your Karthus versus Sett build include Rabadon's Deathcap, Malignance, and Liandry's Torment. When Karthus used at least these three items in his build, he performed much better countering Sett than with most other common item sets. In fact, Karthus boasted an average win rate of 46.9% when countering Sett with these items in his kit.
To have the highest likelihood of crushing Sett as Karthus, you should use the Dark Harvest, Cheap Shot, Eyeball Collection, Ultimate Hunter, Gathering Storm, and Transcendence runes from the Domination and Sorcery rune sets. Of all the rune sets players used for Karthus vs Sett battles, this combo of runes yielded the greatest win rate. Notably, these runes provided a 46.9% win rate overall.
If you need to see Karthus x Sett tips and counter builds for a an individual division, please select one from the selection menu displayed above. If viewing for the first time, the statistics and build suggestions shown are computed using all matches completed with these champs.