Prioritize disrupting Karthus's full clears by invading early and punishing isolated camps to deny his scaling tempo.
Use Kha'Zix's mobility and isolation damage to control river and jungle entrances, avoiding grouped fights where Karthus excels with his global damage.
Jungle Plan
Invade Karthus during his first clears and force him off camps before level 6 to delay his scaling.
Fight for river control and Scuttle when your lanes can support early aggression and isolate Karthus.
Use fog and vision denial to set up picks around dragon and Rift Herald before starting objectives.
Danger windows
Be cautious invading when Karthus's lanes lack pressure and cannot collapse, as he can full clear and reset tempo.
Avoid isolated river fights without vision control to prevent being counter-invaded or collapsed on.
Watch for forced smite fights at dragon or Herald where Karthus's team may group and reduce your isolation advantage.
Early game
Start with a clear path that allows quick access to river Scuttle and isolated enemy camps for early invades.
Contest first Scuttle only if nearby lanes have priority to avoid collapsing on you.
Avoid prolonged fights early; focus on clean picks or forcing Karthus off camps before he completes his first full clear.
Power spikes
At level 6, use (R) stealth to reposition and isolate Karthus or his teammates before objectives.
After first damage item, increase invade pressure to punish Karthus's weaker early dueling and slow clears.
Respect Karthus's level 6 (R) global damage that can finish low-health allies after skirmishes.
Win conditions
Convert early invade leads into denying Karthus farm and objective control by securing vision and picks.
Use isolation damage and fog control to create picks before starting dragon or Rift Herald.
Snowball skirmishes by picking off isolated targets and forcing Karthus into grouped fights where he is less effective.
Tip: For Kha'Zix vs Karthus, read overview, trading pattern, and danger windows first for a fast Jungle lane check.
