Flurry of Blows

Flurry of Blows is the Watcher's signature free attack: 0 Energy, deals 4 damage (6 upgraded), and every time you change stances it returns from the discard pile to your hand. The stance-return trigger is what makes this card extraordinary. In a typical Watcher turn where you cycle Calm -> Wrath -> Calm or vice versa, Flurry of Blows comes back to your hand for each transition, effectively giving you unlimited free plays as long as you keep switching stances.

In Wrath, Flurry of Blows deals double damage (8 per play, or 12 upgraded), and since it costs 0, every stance switch is essentially a free 8-damage hit. A single combat with two stance changes produces 16+ free damage; aggressive cycling can generate far more. This card is a core reason why Watcher's burst potential is so high. Upgrading is high priority to push the damage into more meaningful territory.