Diana vs Katarina Mid Matchup

Diana Mid wins 54.4% of 3,033 Low Elo games against Katarina Mid, +2.4 points vs expected, 2-patch window 26.19-26.20.

Researched on LoL patch 26.20. Tips are written to hold at any rank; stats come from Low Elo ranked games up to patch 26.20.

Why Diana is favored

Diana's Pale Cascade(W) can absorb Katarina's burst, then her shielded, attack-speed-enhanced follow-up wins the direct trade. Katarina is better off avoiding the 1v1 and looking for skirmishes where takedown resets can keep her active through the fight.

How to play as Diana

Hold Moonfall(R) for Katarina's Death Lotus(R); the pull interrupts her channel and turns her committed all-in into a losing trade.

Pale Cascade(W) shields Diana while its spheres deal damage, and Moonsilver Blade(P) speeds up her attacks after spells and empowers every third strike; together they let her absorb Katarina's burst and punish the follow-up trade.

If Crescent Strike(Q) marks Katarina, Lunar Rush(E) can dash to her without going on cooldown, so Diana can keep chasing after Katarina uses Shunpo(E) to reposition.

How to play as Katarina

Avoid trading into Diana's shield and Crescent Strike. Use Shunpo(E) to dodge Q or disengage, then look for a brief trade after she has spent those defenses instead of committing into her shielded autos.

If Diana controls the lane, protect your health and farm rather than forcing a solo kill; look for skirmishes where Katarina's takedown cooldown resets can carry her through a fight.

Sources

These notes come from r/KatarinaMains and LoL Wiki, checked against the champions' abilities.