Clever use of enemy ultimates can open up new possibilities to approach teamfights.
Wait for you or your enemy to reach low health before using Kingslayer for maximum effect.
Space out your ability usage to get maximum effect from Petricite Burst.
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 stats provided here emphasize several valuable Sylas against Karthus counter statistics that can help you realize the differences between these two champions. Sylas’s KDA ratio ([kills + assists] / deaths) of NaN is better than Karthus’s ratio of NaN, showing that Sylas may be more central to his team's team fighting effectiveness than Karthus..
Sylas normally has a slightly larger longest killing spree than his matchup does. Typically, he takes more damage than Karthus. This often reflects differing health capacities, yet it can also show that the champion with higher health has less mobility and thus is not able to escape additional harm when engaged or poked.
Both League of Legends champs are great. Both have their pros and cons. In League's current meta, Sylas usually wins when trying to fight Karthus, with a 51.8% win rate. Thus, Sylas makes a good counter for Karthus.
While Sylas does have a higher win rate than Karthus, when facing one another, Sylas also has a lower level of difficulty that makes him a less difficult character to develop with. You still need to be cautious when picking Sylas into Karthus.
Moreover, Sylas also has only a small amount of utility and CC, a similar amount to Karthus. This makes her just as valuable during teamfights, especially when trying to counter champions with a lot of burst damage.
While there is not a single best champion overall in League of Legends, in Sylas vs Karthus matchups, Sylas is the better champion with a higher win rate, less champion complexity, and a similar amount of utility to help out your allies during late stage team fights.
Sylas is a decent counter for Karthus. You will do well by focussing your play on keeping up your gold income and taking out objectives. If you do that, you should do very well as Sylas against Karthus.
If you would like to truly master Sylas in order to counter Karthus during both the early game and mid / late game phases of League of Legends, you should continue reading to gather a few extra tricks and insights into this matchup. If you mind the build and suggestions shown here, you will grow your win rate significantly and be that much closer to League of Legends pro players.
Sylas often accumulates a similar amount of CS compared to Karthus. Champs who on average don't get many minion kills often don't have to have much CS to be valuable teammates, such as support champions. They 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, often need a lot of items to be effective. In either situation, try to exceed the numbers reported here to do well.
The most crucial items to prioritize in your Sylas versus Karthus build include Rabadon's Deathcap, Zhonya's Hourglass, and Stormsurge. When Sylas used at least these three items in his build, he performed a lot better when fighting Karthus than with many other commonly used counter builds. In fact, Sylas boasted an average win rate of 51.8% when playing against Karthus with this counter build.
To have the greatest probability of annihilating Karthus as Sylas, you should use the Electrocute, Sudden Impact, Eyeball Collection, Relentless Hunter, Scorch, and Transcendence runes from the Domination and Sorcery rune sets. Out of all the rune combinations players chose for Sylas vs Karthus counters, this mixture of runes yielded the highest win rate. Moreover, these runes gave a 51.8% winrate overall.
By default, tips, stats, and builds on how to beat Karthus as Sylas are displayed for all skill levels combined. If you want to narrow the stats and builds to a distinct player tier, you may use the selection menu earlier in the counter matchup guide.