Matchup

Fizz
Fizz
46%
54%

vs

47.7%

over 107 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

Lich Bane
1Mage
Stormsurge
2vs Tank
Zhonya's Hourglass
3vs AD

Standard

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

Summoner spells

41196%
11143%

Anti AP

Mercury's Treads
4vs CC
Banshee's Veil
5vs AP

Anti Tank

Shadowflame
5vs Tank
Void Staff
vs Tank
Cryptbloom
vs Tank

DPS

Dusk and Dawn
Mage tank
Nashor's Tooth
DPS
Rabadon's Deathcap
Mage
Riftmaker
Mage tank
Hextech Rocketbelt
Mage tank
Statikk Shiv
DPS
Cosmic Drive
Mage tank

Other options

Mejai's Soulstealer
100.0% WR2 games
PrecisionPrecision
Press the AttackPress the Attack
TriumphTriumph
Legend: AlacrityLegend: Alacrity
Coup de GraceCoup de Grace
DominationDomination
Treasure HunterTreasure Hunter
Sudden ImpactSudden Impact
Attack SpeedAdaptive ForceHealth Scaling

Power Spikes

Strength by game phase

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