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 provided here show several vital Karthus versus Rell counter stats that can help us explain the distinctions between this pair of champs. Karthus’s KDA ratio ([kills + assists] / deaths) of NaN is more than Rell’s ratio of NaN, demonstrating that Karthus may be more central to his team's team fighting effectiveness than Rell. This observation is in large part caused by the difference in kills.
Karthus often has a much larger longest killing spree than his opponent does. Typically, he takes more damage than Rell. This often reflects differing health capacities; however, it can also hint that the one champ has less agility and thus is unable to escape further harm when engaged or poked.
Both LoL champions are great. Both champs have their pros and cons. In the game's current meta, Karthus usually loses when playing against Rell, with a 48.6% win rate. Therefore, Karthus makes a bad counter for Rell.
While Karthus does have a lower win rate than Rell, when on opposite teams, Karthus also has a much greater level of difficulty that makes him a more challenging champion to learn and master. You should be careful when picking Karthus into Rellas his relative depth means that you may not be able to reach his full potential without a significant amount of practice beforehand.
Additionally, Karthus has some amount of CC and other utility, a similar amount to Rell. This often makes her just as valuable during teamfights, especially when facing champions with a lot of burst damage.
While there is not a single best champion for every situation in League of Legends, in Karthus vs Rell matchups, Rell is the better champ with a lower win rate, more champion depth, and a similar amount of utility to help out your team members during late stage team fights.
Karthus is a somewhat poor counter for Rell. Focus your tactics on increasing your CS and clearing objectives. If you are able to do that, you should do very well as Karthus against Rell.
To truly master Karthus in order to counter Rell during both the laning and mid / late game phases of League of Legends, you should continue reading to learn a few extra tricks and insights into this matchup. If you listen to the build and tips displayed above, you will grow your win rate significantly and be closer to League of Legends pro players.
Karthus usually picks up much more CS as Rell. Champs who on average don't acquire many minion kills typically don't need much CS to be effective, such as sup champs. They are capable of scaling properly off of their skills, stats, and first items alone. Yet, champs with a lot of CS, such as hyper-carries, typically need a lot of items to be effective. In either case, try to exceed the values displayed here to do well.
The most important items to focus on in your Karthus versus Rell build consist of Malignance, Stormsurge, and Liandry's Torment. When Karthus bought at least these three pieces in his build, he did a lot better when facing Rell than with many other commonly used item sets. In fact, Karthus boasted an average winrate of 48.6% battling Rell with this build.
To have the best likelihood of crushing Rell 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. Of all the runes players chose for Karthus vs Rell counterpicks, this mix of runes resulted in the best win rate. Notably, these runes gave a 48.6% winrate overall.
If you want to get Karthus versus Rell tips and counter stats for a a distinct player tier, please select one from the selection menu provided above. If viewing for the first time, the stats and strategies shown are computed using all rounds run with these champs.