Matchup
You are stronger late game — farm safe and avoid early trades.
Build vs Karthus
Build adapted to this matchup
Starting items
Core build
Standard
Summoner spells
80%
20%Anti AD
Anti CC
Other options
Sorcery
Summon Aery
Manaflow Band
Transcendence
Scorch
Resolve
Revitalize
Font of Life
Power Spikes
Strength by game phase
Yuumi
KarthusKarthus's abilities
Passive, spells and ultimate
Upon dying, Karthus enters a spirit form that allows him to continue casting spells.
Cooldowns
Cooldowns by spell rank
| Level | Q | W | E | R |
|---|---|---|---|---|
| 3 | 0s | 15s | 0.5s | – |
| 6 | 0s | 15s | 0.5s | 3m20 |
| 9 | 0s | 15s | 0.5s | 3m20 |
| 11 | 0s | 15s | 0.5s | 3m |
| 16 | 0s | 15s | 0.5s | 2m40 |
| 18 | 0s | 15s | 0.5s | 2m40 |
Playing against Karthus
How to counter and exploit weaknesses
Zhonya's, Edge of Night, and Banshee's block/cancel his R — buy one of these items if Karthus focuses you.
His Q deals double damage on isolated targets: stay in your minions or near allies to split the damage.
Shields, Soraka R, and heals can counter his R if well-timed — save an emergency heal for Requiem.
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