Kai’Sa vs Karthus Counter Pick

42.6% across 564 games on patch 16.13.1 is the sort of number that points to a kit mismatch rather than a stat gap, and this pairing fits. Karthus deals magic damage from 450 attack range, seventy-five short of Kai’Sa’s 525, and the range column barely matters because almost none of his damage arrives as an attack.

Wall of Pain is the specific problem. It reduces movement speed and magic resistance for anything walking through it, stripping the one defensive stat that answers the rest of his kit while slowing a champion whose only dash, Killer Instinct, travels toward an enemy rather than away from one. Defile drains health from everything in range for as long as he can pay for it, and Lay Waste deals increased damage to isolated targets, which is the exact position a carry occupies while farming a side wave. Death Defied keeps him casting after death, so a favorable trade does not end the pressure, and Requiem reaches every enemy champion regardless of distance, which turns a won skirmish elsewhere on the map into a lost one. Kai’Sa’s outs are early: 640 health against 620, 59 attack damage against 46, and Second Skin’s Plasma stacking rewards short aggressive trades before he has the mana to sustain Defile. Past that window his 2,490 health at level 18 exceeds her 2,374. The Karthus page covers his scaling.