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.
Get boots early when playing against Syndra, they'll help you avoid many of her spells.
Attack Syndra after she's used Scatter the Weak, it has a long cooldown so she'll be vulnerable.
At max rank Syndra's spells gain bonus effects and change in appearance.
The stat comparisons provided here emphasize several vital Karthus vs. Syndra counter stats that can help you understand the differences between the two. Karthus’s KDA ratio ([kills + assists] / deaths) of NaN is greater than Syndra’s KDA ratio of NaN, indicating that Karthus may be more central to his team's team fighting effectiveness than Syndra..
Karthus usually has a similar longest killing spree as his foe does. Typically, he receives more damage than Syndra. This typically indicates different amounts of tankyness, but it can also imply that the one champ has less mobility and thus is unable to flee from further damage when engaged or poked.
Both League champs are great. Both have their pros and cons. In League's current meta, Karthus usually fairs equally well when facing off against Syndra, with a 49.1% win rate. As a result, Karthus makes an ok counter for Syndra.
While Karthus does have a lower win rate compared to Syndra, when facing one another, Karthus also has a lower learning curve that makes him a less complex character to develop with. You still need to be cautious when picking Karthus into Syndraas his relative depth means you may not be able to reach his full potential without a significant amount of practice beforehand.
Moreover, Karthus also has some amount of CC and other utility, a similar amount to Syndra. This makes her just as valuable during teamfights, especially when facing champions with a lot of burst damage.
While there is not one best champion in League of Legends, in Karthus vs Syndra matchups, Syndra is the better champion with a similar win rate, less champion complexity, and a similar amount of utility to help out your allied champions during late stage team fights.
Karthus is a somewhat poor counter to Syndra. Focus your strategy on keeping up your gold and cs and destroying objectives. If you are able to do that, you should be able to stand on your own as Karthus against Syndra.
If you would like to truly master Karthus to counter Syndra during both the lane 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 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 typically gets less CS relative to Syndra. Champs who typically don't acquire many minion kills typically don't have to have much CS to be effective, such as sup champs. They are able to scale well off of their abilities and first items alone. Yet, champions with large amounts of CS, such as hyper-carries, usually have to have several high cost items to be effective. In either case, try to surpass the numbers reported on this page to do well.
The top items to prioritize in your Karthus versus Syndra build include Rabadon's Deathcap, Stormsurge, and Liandry's Torment. When Karthus bought at least these three items in his build, he performed a lot better against Syndra than with most other typical counter builds. In fact, Karthus had an average winrate of 49.1% battling Syndra with this counter build.
To have the best likelihood of annihilating Syndra as Karthus, you should equip 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 picked for Karthus vs Syndra clashes, this set of runes resulted in the best win rate. In fact, these runes gave a 49.1% win rate overall.
By default, tips, stats, and builds on how to beat Syndra as Karthus are given for every ranked division. If you want to scope the statistics and builds to an individual rank, you may use the selection menu located earlier on the page.