Papercut

Mouse fights: cursor above your fighter's waist guards high, below guards low. Left click light slash, Right click heavy slash. Left click or Q during a heavy's wind-up feints.

Keyboard moves: A D walk (double-tap to dash), Space or W jump, Esc back to this menu.

The rule: hit someone while their heavy winds up, or right after they miss, and it's a counter cut: instant K.O. Flick your guard to the right height just before a hit lands to parry, then answer with a riposte.