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 shown on this page emphasize several vital Senna vs. Karthus counter statistics that may help us grasp the differences between the two. Senna’s KDA ratio ([kills + assists] / deaths) of NaN is better than Karthus’s KDA ratio of NaN, demonstrating that Senna may be more central to her team's team fighting capability than Karthus..
Senna normally has a slightly smaller longest killing spree than her counter does. On average, she takes less damage than Karthus. This commonly reflects differing health capacities, but it can also imply that the one champion has less agility and thus is unable to escape further harm when engaged or poked.
Both LoL champions are great. Both have their pros and cons. In League's current meta, Senna usually wins when facing off against Karthus, with a 53.5% win rate. Thus, Senna makes a great counter for Karthus.
While Senna does have a higher win rate than Karthus, when on opposite teams, Senna also has a greater difficulty level that makes her a more challenging champ to learn and master. You don't need to be too worried when picking Senna into Karthusas her relative depth means that you may not be able to reach her full potential without a significant amount of practice beforehand.
Moreover, Senna also has a good amount of CC and other utility, a similar amount to Karthus. This often makes her just as valuable during teamfights, especially when facing champions with a lot of burst damage.
While there isn't a single best champion in League of Legends, in Senna vs Karthus matchups, Senna is the better champ with a noticably higher win rate, similar champion depth, and a similar amount of utility to help out your allies during late stage team fights.
Senna is a great counter for Karthus. Make sure you focus your strategy on maximizing your CS and clearing objectives. If you are able to do that, you should do very well as Senna against Karthus.
If you would like to learn all of the intricacies of Senna to counter Karthus during both the lane and mid / late game phases of League of Legends, you should keep reading to gather a few extra lessons on this matchup. If you listen to the build and suggestions shown above, you should grow your win rate significantly and be that much closer to League of Legends pro players.
Senna typically picks up a similar amount of CS compared to Karthus. Champions who typically don't get many minion kills usualy don't have to have much CS to be effective, such as sup champs. They are capable of scaling well off of their skills, stats, and first items alone. Yet, champs with large amounts of CS, such as hyper-carries, typically require many items to be effective. In either case, try to do better than the values displayed on this page to do well.
The most crucial items to use in your Senna versus Karthus build include Infinity Edge, Bloodsong, and The Collector. When Senna incorporated at least these three items in her build, she performed much better against Karthus than with most other typical item sets. In fact, Senna boasted an average winrate of 53.5% battling Karthus with this build.
To have the highest probability of annihilating Karthus as Senna, you should take the Fleet Footwork, Presence of Mind, Legend: Alacrity, Cut Down, Approach Velocity, and Biscuit Delivery runes from the Precision and Inspiration rune sets. Out of all the rune combinations players picked for Senna vs Karthus counterpicks, this blending of runes yielded the best win rate. Moreover, these runes provided a 53.5% win rate overall.
If you need to see Senna vs Karthus tips and counter stats for a a particular player tier, feel free to choose one from the selection menu provided above. If viewing for the first time, the stats and build suggestions shown are computed using all matches played with both champions.