If you stun an enemy with Shocking Orb, follow up with a guaranteed center hit on Eye of Destruction.
It's easier to land Arcanopulse on an enemy when they're moving toward or away from you, rather than side to side.
Eye of Destruction will make landing Arcanopulse easier as the target will be slowed.
Karthus can cast spells for a short duration after he is killed. Move away from his corpse to be safe.
Make sure you always have enough health to survive Requiem, even if you have to go back to the base more frequently to heal.
The stats shown on this page underscore several influential Xerath vs. Karthus counter stats that can help us realize the differences and similarities between the pair. For instance, Xerath’s KDA ratio ([kills + assists] / deaths) of NaN is greater than Karthus’s KDA ratio of NaN, highlighting that Xerath may be more central to his team's team fighting potential than Karthus..
Xerath typically has a similar longest killing spree as his foe does. Commonly, he receives less damage than Karthus. This typically indicates differing health capacities, yet it can also illustrate that the champ with more HP has less mobility and thus is unable to kite away from further harm when poked or engaged.
Both League champs are great champions. Both have their pros and cons. In League's current meta, Xerath usually wins when playing against Karthus, with a 54.1% win rate. Therefore, Xerath makes a great counter for Karthus.
While Xerath does have a much higher win rate than Karthus, when on opposite teams, Xerath also has a greater learning curve that makes him a more time consuming champion to pick up and master. You don't need to be too worried when picking Xerath into Karthusas his relative depth means that you may not be able to unleash his full potential without a lot of practice beforehand.
Moreover, Xerath also has some amount of utility and CC, a similar amount to Karthus. This often makes her just as valuable during teamfights, especially when trying to counter champions with a lot of burst damage.
While there isn't one best champion overall in League of Legends, in Xerath vs Karthus matchups, Xerath is the better champion with a noticably higher win rate, more champion depth, and a similar amount of utility to help out your teammates during teamfights.
Xerath is a great counter to Karthus. You will do well by focussing your actions on maximizing your gold income and clearing objectives. If you are able to do that, you should be able to stand on your own as Xerath against Karthus.
To truly master Xerath in order to counter Karthus during both the lane and mid / late game phases of League of Legends, you should continue reading to learn a few extra tips and tricks for this matchup. If you listen to the build and tips displayed above, you will increase your win rate significantly and be that much closer to League of Legends pro players.
Xerath typically gets a similar amount of CS compared to Karthus. Champs who on average don't earn many minion kills typically don't have to have much CS to be effective, such as support champions. They are able to scale well off of their abilities and first items alone. Yet, champs with large amounts of CS, such as hyper-carries, typically require many items to be effective. In either case, try to exceed the numbers displayed here to do well.
The most important items to use in your Xerath versus Karthus build consist of Horizon Focus, Shadowflame, and Luden's Companion. When Xerath used at least these three items in his build, he did a lot better against Karthus than with many other commonly used counter builds. In fact, Xerath had an average win rate of 54.1% when countering Karthus with these items in his kit.
To have the best chance of annihilating Karthus as Xerath, you should equip the First Strike, Magical Footwear, Biscuit Delivery, Cosmic Insight, Manaflow Band, and Scorch runes from the Inspiration and Sorcery rune sets. Out of all the rune builds players picked for Xerath vs Karthus counterpicks, this combo of runes resulted in the highest win rate. In fact, these runes gave a 54.1% winrate overall.
If you want to see Xerath x Karthus tips and matchup stats and build suggestions for a a particular division, please choose one from the selection menu shown above. If viewing for the first time, the statistics and guides shown are computed using all matches with data with both champs.