Matchup

Diana
Diana
47%
53%

vs

52.0%

over 358 games

Karthus
Karthus
17%
83%
Heavy AP damageCountered by stasisSustained DPSHigh burst

Skill matchup

Build vs Karthus

Build adapted to this matchup

Starting items

Scorchclaw Pup
Health Potion

Core build

Hextech Rocketbelt
1Mage tank
Riftmaker
2Mage tank
Zhonya's Hourglass
3vs AD

Standard

Sorcerer's Shoes
4Magic pen
Dusk and Dawn
5Mage tank

Summoner spells

41199%
6111%

Anti AD

Plated Steelcaps
4vs AD
Jak'Sho, The Protean
5vs Hybride
Unending Despair
vs AD
Randuin's Omen
vs AD

Anti Heal

Morellonomicon
6vs Heal

Anti AP

Mercury's Treads
4vs CC
Banshee's Veil
5vs AP
Spirit Visage
vs AP
Kaenic Rookern
vs AP
Abyssal Mask
vs AP
Force of Nature
vs AP

Anti Tank

Shadowflame
5vs Tank
Stormsurge
vs Tank
Void Staff
vs Tank
Bloodletter's Curse
vs Tank

DPS

Dusk and Dawn
Mage tank
Nashor's Tooth
DPS
Liandry's Torment
Mage tank
Rabadon's Deathcap
Mage
Lich Bane
Mage

Other options

Mejai's Soulstealer
83.3% WR6 games
PrecisionPrecision
ConquerorConqueror
TriumphTriumph
Legend: AlacrityLegend: Alacrity
Coup de GraceCoup de Grace
InspirationInspiration
Magical FootwearMagical Footwear
Cosmic InsightCosmic Insight
Attack SpeedAdaptive ForceHealth Scaling

Power Spikes

Strength by game phase

Early (0-15)
Mid (15-30)
Late (30+)
DianaDiana
KarthusKarthus
Aggressive
Careful
Careful

Karthus's abilities

Passive, spells and ultimate

Death Defied (P)

Upon dying, Karthus enters a spirit form that allows him to continue casting spells.

Cooldowns

Cooldowns by spell rank

LevelQWER
30s15s0.5s
60s15s0.5s3m20
90s15s0.5s3m20
110s15s0.5s3m
160s15s0.5s2m40
180s15s0.5s2m40

Playing against Karthus

How to counter and exploit weaknesses

1

Zhonya's, Edge of Night, and Banshee's block/cancel his R — buy one of these items if Karthus focuses you.

2

His Q deals double damage on isolated targets: stay in your minions or near allies to split the damage.

3

Shields, Soraka R, and heals can counter his R if well-timed — save an emergency heal for Requiem.

4

Karthus is immobile and squishy — dive him quickly to eliminate him before he deals continuous damage.

Source: op.gg + LTL Engine · Patch 16.9.1 · May 9, 2026