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.
Olaf has reduced defenses from damage during Ragnarok, despite being immune to disables. If you can't escape from Olaf during Ragnarok, try focusing your damage on him with your teammates.
Olaf becomes more dangerous the lower life he is. Save your disables to finish him off.
Preventing Olaf from reaching his axe will minimize the amount of harassment he can cause in the laning phase.
The stats shown here emphasize some vital Karthus vs. Olaf counter stats that can help you figure out the differences between this pair of champions. Karthus’s KDA ratio ([kills + assists] / deaths) of NaN is greater than Olaf’s KDA ratio of NaN, indicating that Karthus may be more central to his team's team fighting capacity than Olaf. This observation is in large part a result of the differences in assists.
Karthus typically has a similar longest kill spree as his foe does. On average, he takes less damage than Olaf. This often reflects different amounts of tankyness, but it can also imply that the one champ has less agility and thus is not able to flee from additional damage when engaged or poked.
Both LoL champs are great champions. Both have their pros and cons. In League's current meta, Karthus usually loses when playing against Olaf, with a 45.3% win rate. Thus, Karthus makes a poor counter for Olaf.
While Karthus does have a much lower winrate compared to Olaf, when they face off with one another, Karthus also has a much greater level of difficulty that makes him a more complex character to pick up and master. You may get destroyed when picking Karthus into Olafas his relative depth means you may not be able to reach his full potential without a lot of practice beforehand.
Moreover, Karthus has some amount of CC and other utility, a similar amount to Olaf. This makes her just as valuable during team fights, especially when trying to counter champions with a lot of burst damage.
While there is not one best champion in League of Legends, in Karthus vs Olaf matchups, Olaf is the better champion with a much lower win rate, more champion depth, and a similar amount of utility to help out your allied champions during late stage team fights.
Karthus is a garbage counter to Olaf. Make sure you focus your gameplay on maximizing your gold income and destroying objectives. If you can do that, you should do very well as Karthus against Olaf.
To truly master Karthus to counter Olaf during both the laning and mid / late game phases of League of Legends, you should keep reading to pick up a few extra tips and tricks for this matchup. If you listen to the build and suggestions presented here, you will grow your win rate by a lot and be closer to League of Legends pro players.
Karthus on average picks up less CS as Olaf. Champions who typically don't get much CS typically don't require much CS to be valuable teammates, such as support champions. These kinds of champions are capable of scaling properly off of their skills, stats, and first items alone. Yet, champs with large amounts of CS, such as hyper-carries, often have to have many items to be effective. In either situation, try to exceed the numbers shown on this page to do well.
The most important items to prioritize in your Karthus versus Olaf build include Malignance, Stormsurge, and Liandry's Torment. When Karthus incorporated at least these three pieces in his build, he performed a lot better vs Olaf than with most other typical builds. In fact, Karthus boasted an average win rate of 45.3% when playing against Olaf with these items in his kit.
To have the greatest probability of annihilating Olaf as Karthus, Karthus players should use the Dark Harvest, Cheap Shot, Eyeball Collection, Ultimate Hunter, Gathering Storm, and Transcendence runes from the Domination and Sorcery rune sets. Out of all the rune builds players used for Karthus vs Olaf counterpicks, this composite of runes yielded the greatest win rate. Notably, these runes provided a 45.3% winrate overall.
By default, tips, stats, and builds on how to beat Olaf as Karthus are presented for all skill levels combined. If you want to narrow the stats and builds to an individual player tier, you may use the selection menu located above.