Each of Aphelios' weapons have different strengths, so try to find the right situation for your current weapons.
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 stat comparisons provided here show some significant Aphelios against Karthus matchup stats that can help you understand the differences between this pair of champions. Aphelios’s KDA ratio ([kills + assists] / deaths) of NaN is more than Karthus’s KDA ratio of NaN, showing that Aphelios may be more central to his team's team fighting capability than Karthus..
Aphelios usually has a similar longest kill spree as his opponent does. On average, he receives less damage than Karthus. This often reflects differing health capacities; however, it can also indicate that the champion with increased HP has less mobility and thus is not able to escape additional damage when poked or engaged.
Both LoL champions are great. Both champs have their pros and cons. In League's current meta, Aphelios usually loses when trying to fight Karthus, with a 47.2% win rate. As a result, Aphelios makes a bad counter for Karthus.
While Aphelios does have a lower win rate than Karthus, when on opposite teams, Aphelios also has a much greater learning curve that makes him a more difficult champ to develop with. You may get destroyed when picking Aphelios into Karthusas his relative depth means you may not be able to unleash his full potential without a lot of practice beforehand.
Additionally, Aphelios has almost no amount of CC and other utility, a similar amount to Karthus. This makes her just as valuable during team fights, especially when fighting champions with a ton of burst damage.
While there isn't one best champion in League of Legends, in Aphelios vs Karthus matchups, Karthus is the better champion with a lower win rate, more champion depth, and a similar amount of utility to help out your team members during team fights.
Aphelios is a terribly counter for Karthus. Focus your strategy on maximizing your CS and taking out objectives. If you can do that, you should be able to stand on your own as Aphelios against Karthus.
To truly master Aphelios to counter Karthus during both the laning 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 mind the build and tips presented above, you will grow your win rate by a lot and be that much closer to League of Legends pro players.
Aphelios usually accumulates more CS as Karthus. Champs who on average don't earn much CS often don't require much CS to be valuable teammates, such as support champions. They are able to scale properly off of their abilities and first items alone. Yet, champions with a lot of CS, such as hyper-carries, often have to have a lot of items to be effective. In either situation, try to surpass the numbers shown here to do well.
The top items to use in your Aphelios versus Karthus build include Galeforce, Infinity Edge, and The Collector. When Aphelios incorporated at least these three items in his build, he performed much better when facing Karthus than with most other common counter builds. In fact, Aphelios boasted an average win rate of 47.2% when playing against Karthus with this build.
To have the highest probability of coming out on top against Karthus as Aphelios, Aphelios players should use the Fleet Footwork, Overheal, Legend: Bloodline, Cut Down, Taste of Blood, and Ingenious Hunter runes from the Precision and Domination rune sets. Of all the rune combinations we have analyed for Aphelios vs Karthus LoL games, this combo of runes resulted in the best win rate. Moreover, these runes gave a 47.2% winrate overall.
If you want to view Aphelios x Karthus tips and counter builds for a a particular division, feel free to choose one from the selection menu displayed above. By default, the statistics and guides given are calculated using every game finished with both champions.