From Wildermyth Wiki
(Active) End your turn and wait for an enemy to come within range. Hit up to one enemy with a melee attack.
Guardian makes the warrior prepare for battle by ending his turn and striking the next enemy that comes into range.
Sentinel is a possible upgrade to Guardian.
- Guarding in front of weaker party members triggers Walling, reducing incoming damage by 1 and additionally striking any foe that dares to enter melee range.
- Vigilance increases the potential damage the Hero can cause by increasing the amount of reaction strikes per turn.