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.
Keep behind allied minions if Caitlyn is harassing you with Piltover Peacemaker (it deals less damage with each subsequent target).
You can intercept Ace in the Hole's missile from hitting an ally if you stand in its path.
The stat comparisons shown on this page emphasize some significant Karthus against Caitlyn matchup stats that may help you realize the differences between the two. Karthus’s KDA ratio ([kills + assists] / deaths) of NaN is more than Caitlyn’s ratio of NaN, indicating that Karthus may be more central to his team's team fighting capability than Caitlyn..
Karthus normally has a similar longest killing spree as his matchup does. Commonly, he receives more damage than Caitlyn. This is usually reflective of different amounts of tankyness, yet it can also show that the one champ has less agility and thus is not able to escape additional harm when poked or engaged.
Both League of Legends champions are great champions. Both champs have their strengths, weaknesses, and counters. In League's current meta, Karthus usually loses when playing against Caitlyn, with a 46.5% win rate. As a result, Karthus makes a poor counter for Caitlyn.
While Karthus does have a lower win rate compared to Caitlyn, when they face off with one another, Karthus also has a greater level of difficulty that makes him a more time consuming champ to learn. You may get destroyed when picking Karthus into Caitlynas his relative depth means you may not be able to reach his full potential without a significant amount of practice beforehand.
Moreover, Karthus also has some amount of CC and other utility, a similar amount to Caitlyn. This makes her just as valuable during teamfights, especially when trying to counter champions with a ton of burst damage.
While there is not a single best champion overall in League of Legends, in Karthus vs Caitlyn matchups, Caitlyn 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 team fights.
Karthus is a terribly counter for Caitlyn. Focus your actions on maximizing your CS and taking out objectives. If you can do that, you should be able to stand on your own as Karthus against Caitlyn.
To learn all of the intricacies of Karthus in order to counter Caitlyn during both the lane and mid / late game phases of League of Legends, you should continue reading to gather a few extra tips and tricks for this matchup. If you pay attention to the build and stats shown above, you will grow your win rate by a lot and be that much closer to League of Legends pro players.
Karthus most often racks up less CS relative to Caitlyn. Champs who on average don't earn much CS usualy don't need much CS to be valuable teammates, such as sup champs. They are capable of scaling properly off of their abilities and first items alone. Yet, champs with a lot of CS, such as hyper-carries, often need several high cost items to be effective. In either situation, try to surpass the numbers reported on this page to do well.
The best items to prioritize in your Karthus versus Caitlyn build include Rabadon's Deathcap, Malignance, and Luden's Companion. When Karthus used at least these three items in his build, he did much better countering Caitlyn than with many other commonly used builds. In fact, Karthus boasted an average win rate of 46.5% when countering Caitlyn with these items in his kit.
To have the greatest probability of beating Caitlyn 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. Of all the runes players picked for Karthus vs Caitlyn counterpicks, this combo of runes yielded the best win rate. Moreover, these runes gave a 46.5% winrate overall.
By default, tips, stats, and builds on how to beat Caitlyn as Karthus are shown for all ranked divisions. To scope the stats and builds to a distinct rank, you should use the selection menu located at the top of this page.