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.
The stat comparisons shown here clarify several significant Karthus vs. Fiddlesticks counter statistics that may help you interpret the distinctions between the pair. As an example, Karthus’s KDA ratio ([kills + assists] / deaths) of NaN is more than Fiddlesticks’s ratio of NaN, showing that Karthus may be more central to his team's team fighting capability than Fiddlesticks..
Karthus often has a slightly larger longest kill spree than his counter does. Typically, he takes less damage than Fiddlesticks. This commonly reflects differing health capacities; however, it can also show that the champ with higher health has less mobility and thus is not able to flee from further harm when poked or engaged.
Both League of Legends champions are great champions. Both have their strengths, weaknesses, and counters. In the game's current meta, Karthus usually fairs equally well when taking on Fiddlesticks, with a 49.1% win rate. Therefore, Karthus makes an ok counter for Fiddlesticks.
While Karthus does have a lower win rate compared to Fiddlesticks, when on opposite teams, Karthus also has a lower difficulty level that makes him a less complex character to pick up and master. You still need to be cautious when picking Karthus into Fiddlesticksas his relative depth means that you may not be able to unleash his full potential without a significant amount of practice beforehand.
Additionally, Karthus has some amount of CC and other utility, a similar amount to Fiddlesticks. This makes her just as valuable during teamfights, especially when trying to counter champions with a ton of burst damage.
While there isn't one best champion for every situation in League of Legends, in Karthus vs Fiddlesticks matchups, Fiddlesticks is the better champion with a similar win rate, less champion complexity, and a similar amount of utility to help out your allies during late stage team fights.
Karthus is a somewhat poor counter to Fiddlesticks. Focus your play on keeping up your CS and clearing objectives. If you do that, you should do very well as Karthus against Fiddlesticks.
If you would like to truly master Karthus to counter Fiddlesticks during both the early game and mid / late game phases of League of Legends, you should continue reading to pick up a few extra tips and tricks for this matchup. If you mind the build and stats shown above, you will increase your win rate by a lot and be that much closer to League of Legends pro players.
Karthus on average accumulates more CS compared to Fiddlesticks. Champs who on average don't acquire much CS often don't have to have much CS to be effective, such as supports. These kinds of champions are able to scale properly off of their skills, stats, and first items alone. Yet, champs with a lot of CS, such as hyper-carries, usually require a lot of items to be effective. In either case, try to exceed the numbers reported on this page to do well.
The most important items to focus on in your Karthus versus Fiddlesticks build include Malignance, Stormsurge, and Liandry's Torment. When Karthus included at least these three pieces in his build, he did a lot better when fighting Fiddlesticks than with many other typical builds. In fact, Karthus had an average win rate of 49.1% when playing against Fiddlesticks with these items in his kit.
To have the greatest probability of coming out on top against Fiddlesticks as Karthus, Karthus players 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. Out of all the rune builds players used for Karthus vs Fiddlesticks LoL games, this set of runes yielded the highest win rate. In fact, these runes averaged a 49.1% winrate overall.
If you would like to view Karthus versus Fiddlesticks tips and counter builds for a a particular skill level, please choose one from the selection menu provided above. By default, the stats and guides displayed are computed using every match run with these champs.