Matchup

Heavy AP damageCountered by stasisSustained DPSHigh burst

Build vs Karthus

Build adapted to this matchup

Starting items

Doran's Shield
Health Potion

Core build

Tear of the Goddess
1
Bloodletter's Curse
2vs Tank
Seraph's Embrace
3Mage

Standard

Boots of Swiftness
4vs Slow
Hollow Radiance
5vs AP

Summoner spells

41263%
41425%

Anti AD

Plated Steelcaps
4vs AD
Unending Despair
5vs AD
Sunfire Aegis
vs AD
Randuin's Omen
vs AD
Frozen Heart
vs AD

Anti Heal

Thornmail
6vs Hybride

Anti AP

Mercury's Treads
4vs CC
Hollow Radiance
5vs AP
Spirit Visage
vs AP

Other options

Fimbulwinter
Survival
Jak'Sho, The Protean
vs Hybride
100.0% WR1 games
ResolveResolve
Grasp of the UndyingGrasp of the Undying
DemolishDemolish
Second WindSecond Wind
OvergrowthOvergrowth
SorcerySorcery
TranscendenceTranscendence
Manaflow BandManaflow Band
Attack SpeedHealth ScalingHealth Scaling

Power Spikes

Strength by game phase

Early (0-15)
Mid (15-30)
Late (30+)
MaokaiMaokai
KarthusKarthus
Neutral
Neutral
Neutral

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