Use early jungle pressure and fast clears to deny Karthus safe farming and prevent him from stacking camps freely.
Control river vision and Scuttle crabs to limit Karthus's ability to contest objectives or set up safely for his global plays.
Prioritize objective control and repeated ganks to snowball lanes before Karthus hits his major scaling spikes.
Jungle Plan
Path to gank lanes where you can chain CC with (W) and (E) to secure kills or force flashes, then convert successful ganks into immediate dragon or Herald starts.
Fight for first Scuttle only when your lanes have priority and use (Q) plus Smite to secure early objectives quickly.
Track Karthus's jungle path and counter-gank when he shows on the opposite side of the map to deny his tempo and scaling.
Danger windows
Avoid isolated river fights or forced smite contests during Karthus's level 6 ultimate window.
Be cautious during low-health clears where Karthus can punish with ranged (Q) damage or call for lane assistance.
Watch for enemy laners with priority who can collapse for counterganks when you contest river or invade early.
Early game
Start with a quick clear on your side to reach level 3 before Karthus and contest the first Scuttle aggressively when nearby lanes have priority.
Avoid extended invades without lane priority since Karthus can punish overextensions with his ranged (Q) and global (R) damage.
Use your (W) from fog for unexpected ganks to force Karthus into defensive farming rather than free clears.
Power spikes
Level 3 and first objective spawn are your major spikes; use (Q) plus Smite to secure dragons or Heralds and pressure Karthus's jungle.
Respect Karthus's level 6 spike when his (R) enables global damage; avoid isolated fights during this window.
Punish Karthus's ultimate cooldown by invading or forcing skirmishes immediately after (R) expires.
Win conditions
Convert early jungle pressure and Scuttle control into denying Karthus's farm and forcing him off key camps.
Use superior early dueling with CC chains and (Q) sustain to secure dragons and Rift Heralds before Karthus can respond.
Coordinate ganks and counterganks leveraging your crowd control to snowball lanes and extend map pressure, preventing Karthus from safely scaling.
Tip: For Nunu & Willump vs Karthus, read overview, trading pattern, and danger windows first for a fast Jungle lane check.
