Matchup

Heavy AP damageCountered by stasisSustained DPSHigh burst

You are stronger early — look to snowball before your opponent scales.

Build vs Karthus

Build adapted to this matchup

Starting items

Doran's Blade
Health Potion

Core build

Titanic Hydra
1Bruiser
Hullbreaker
2Bruiser
Overlord's Bloodmail
3HP

Standard

Boots of Swiftness
4vs Slow
Black Cleaver
5vs Tank

Summoner spells

41238%
41438%

Anti AD

Plated Steelcaps
4vs AD
Guardian Angel
5vs AD
Randuin's Omen
vs AD

Anti Heal

Mortal Reminder
6vs Hybride

Anti Tank

Black Cleaver
5vs Tank

Other options

Sterak's Gage
Survival
100.0% WR2 games
PrecisionPrecision
ConquerorConqueror
TriumphTriumph
Legend: AlacrityLegend: Alacrity
Cut DownCut Down
ResolveResolve
Second WindSecond Wind
OvergrowthOvergrowth
Attack SpeedAdaptive ForceHealth Scaling

Power Spikes

Strength by game phase

Early (0-15)
Mid (15-30)
Late (30+)
KledKled
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