Matchup

Heavy AP damageCountered by stasisSustained DPSHigh burst

Build vs Karthus

Build adapted to this matchup

Starting items

Doran's Blade
Health Potion

Core build

Essence Reaver
1DPS
Liandry's Torment
2Mage tank
Malignance
3Mage

Standard

Boots of Swiftness
4vs Slow
Infinity Edge
5DPS

Summoner spells

41471%
41226%

Anti AD

Plated Steelcaps
4vs AD
Death's Dance
5vs AD
Guardian Angel
vs AD

Anti Heal

Mortal Reminder
6vs Hybride

Anti AP

Mercury's Treads
4vs CC
Maw of Malmortius
5vs AP

Anti Tank

The Collector
5vs Tank
Lord Dominik's Regards
vs Tank
Voltaic Cyclosword
vs Tank
Serpent's Fang
vs Tank
Youmuu's Ghostblade
vs Tank

DPS

Infinity Edge
DPS
Immortal Shieldbow
DPS
100.0% WR1 games
SorcerySorcery
Deathfire TouchDeathfire Touch
Nimbus CloakNimbus Cloak
TranscendenceTranscendence
ScorchScorch
PrecisionPrecision
Cut DownCut Down
Legend: HasteLegend: Haste
Adaptive ForceAdaptive ForceHealth

Power Spikes

Strength by game phase

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

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