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.
Timing Janna's ultimate can push enemies away from a wounded ally or even separate enemies.
Eye of the Storm can be used on allied turrets.
Quickly firing a Howling Gale without the charge up can be used to heavily disable the other team.
The Karthus Janna synergy stats shown here demonstrate the areas of his gameplay that do better (or worse) when paired with Janna, compared to his overall stats. Significant differences are areas of focus that highlight how his gameplay changes when paired with this other champion.
Overall, Karthus sees a very large drop in his KDA (ratio of kills and assists to deaths) when paired with Janna. His KDA decreased from NaN to NaN. This worsening shows that Janna helps Karthus perform poorer in competitive League matches. Yet, the small difference demonstrates that this performance change is only marginal.
When Karthus is paired with Janna, he observes a little drop in his total damage output. This difference may indicate that Janna does not help protection for him to deal more damage or that her presence on the team also helps increase the round's duration. Similarly, when Karthus is played alongside Janna on the same side, he usually scores many fewer killing sprees compared to when he plays without Janna. This is contrasting evidence that he is worse when playing with Janna.
Moreover, when Karthus plays with Janna on the same team, he usually takes a little less damage than when he fights alone. Receiving not as much damage could indicate that Janna does a decent job of covering Karthus during team fights.
There is no top synergy for Karthus that will 100% of the time be his top synergy. Yet, overall, Janna is a pretty good teammate for Karthus. By playing on the same team as Karthus, she improves their win rate by 1.6% to 48.9%. This proves that there is a somewhat important bond between Karthus and Janna that results in them performing better together than alone.
Janna has a lower difficulty than Karthus. That means Karthus players don't need to be careful when finding Janna allies to play with, as they will require a relatively low level of skill to play well with you.
When playing alongside, you should observe an overall large increase in your team’s capability to to do a lot of AP damage. Combined, these two are able to dish out a surprising amount of magic type damage.
Although, by bringing Karthus and Janna together, you probably will not be providing your side a great deal of anti-tank damage dealing potential. Make sure to have other champs on your team that fills this relative gap in their capabilities.
Regardless of the ability of your Janna ally, you need to focus on maximizing your income, outlasting your enemies, and clearing objectives. If you do this, you should do well, regardless.
If you would like to learn all of the intricacies of Karthus to pair well with Janna during both the lane and mid / late game phases of League of Legends games, you should keep reading to master a few extra tips and tricks for this champion pairing. If you listen to the build and suggestions displayed above, you will increase your win rate by a lot.
The most important items to focus on in your Karthus and Janna synergy build consist of Rabadon's Deathcap, Malignance, and Liandry's Torment. When Karthus included at least these three pieces in his build, he did significantly better when fighting alongside Janna than with many other common item sets. In fact, Karthus had an average win rate of 48.9% helping carry Janna with this build.
To have the greatest likelihood of defeating your oponents, you should use the First Strike, Magical Footwear, Future's Market, Cosmic Insight, Eyeball Collection, and Ultimate Hunter runes from the Inspiration and Domination rune sets. Of all the rune sets that we analyzed for this champion pairing, this sequence of runes yielded the highest win rate. Moreover, these runes provided a 48.9% winrate overall.
By default, tips, stats, and builds on how to pair Janna with Karthus are given for all ranked divisions combined. If you want to narrow the stats and builds to a specific rank, you may use the selection menu earlier in the counter matchup guide.