1It's Killing Time
GoldAfter casting your Ultimate, mark all enemies and store up damage you deal to them. When it ends, detonate the damage.
BARAM: Mayhem · Patch 16.20KarthusARAM: Mayhem build
the Deathsinger
- ARAM: Mayhem rank
- #114 / 173
- Top augment
- It's Killing Time
Tier B
Recursion · Combusting Interest
Karthus best augments
All augments →1
2Recursion
GoldGain 60 Ability Haste.
3Combusting Interest
GoldBurn and damage-over-time on champions generate gold.
4Eureka
PrismaticGain Ability Haste equal to 30% Ability Power.
5Ultimate Revolution
PrismaticRefresh your Ultimate after casting it (75 seconds Cooldown or reset on death).
6Magic Missile
GoldDealing Ability damage fires 3 missiles, each dealing percent max Health true damage based on distance traveled.
7Ult Bot
PrismaticYour Ability Haste only applies to your Ultimate, but is 50% more effective. Gain 100 Ability Haste.
8Phenomenal Evil
GoldPermanently gain 1 Ability Power when you damage enemy champions with Abilities. If taken as your second Augment, starts with 40 Ability Power.
9Purist - Caster
SilverGain percent cooldown reduction and convert all of your Attack Speed into Ability Haste.
10Transmute: Prismatic
GoldGain a random 
Prismatic Augment.
Augment order comes from OP.GG. Runes, items and skill order below come from regular ARAM games on the same map.
Recommended Karthus build
Most played and most reliable choicesRunes
Spells
Skill priority
Q
E
WStart
Boots
Core
Karthus runes
47.9% WR37.7% pick23,854 games
Domination
Sorcery
47.2% WR24.6% pick15,579 games
46.4% WR8.8% pick5,595 games
49.6% WR4.2% pick2,630 games
Karthus skill order
49.3% WR49.5% pick24,772 games
Q123456789101112131415W123456789101112131415E123456789101112131415
R123456789101112131415Karthus summoner spells
48.9% WR66.9% pick41,437 games
47.1% WR7.9% pick4,890 games
Power curve
Steady through the whole game
47.8
50.0
53.4
53.8
45.7
Win rate (%) by game length in minutes. Dashed line = 50%.
Karthus items
First three completed items48.6%
15.1% · 8,037 games
53.2%
5.1% · 2,695 games
46.6%
4.3% · 2,296 games
47.1%
4.3% · 2,276 games
51.2%
3.2% · 1,721 games
Start47.4%
47.0% · 28,731 games
Start50.2%
15.2% · 9,256 games
Boots47.9%
90.9% · 39,632 games
Boots47.2%
7.6% · 3,326 games
Boots42.4%
0.6% · 269 games
Karthus situational items
How often each item ends up in the final buildMalignance73.2% · 47.3%Liandry's Torment69.1% · 49.7%Shadowflame59.9% · 48.8%
Blackfire Torch39.4% · 51.2%
Rabadon's Deathcap37.8% · 50.1%
Void Staff20.1% · 49.8%
Stormsurge14.5% · 50.6%
Rylai's Crystal Scepter12.3% · 53.5%
Seraph's Embrace9.7% · 47.2%
Morellonomicon9.1% · 47.3%
Luden's Echo7.8% · 47.8%
Oblivion Orb6.7% · 47.6%
Zhonya's Hourglass5.3% · 46.3%
Tear of the Goddess4.1% · 45.8%
Horizon Focus3.3% · 50.0%
Cryptbloom2.0% · 52.9%Karthus abilities
PassiveDeath Defied
Upon dying, Karthus enters a spirit form that allows him to continue casting spells.
QLay Waste
Karthus unleashes a delayed blast at a location, dealing damage to nearby enemies. Deals increased damage to isolated enemies.
Cooldown: 0s · Cost: 20/25/30/35/40WWall of Pain
Karthus creates a passable screen of leeching energy. Any enemy units that walk through the screen have their Move Speed and Magic Resist reduced for a period.
Cooldown: 15s · Cost: 70EDefile
Karthus passively steals energy from his victims, gaining Mana on each kill. Alternatively, Karthus can surround himself in the souls of his prey, dealing damage to nearby enemies, but quickly draining his own Mana.
Cooldown: 0.5s · Cost: 30/42/54/66/78RRequiem
After channeling for 3 seconds, Karthus deals damage to all enemy champions.
Cooldown: 200/180/160s · Cost: 100