Auto-translated
First of all, the hero's units deal double damage to their sworn enemies with a significant probability (40%). If the hero has the "deadly shot" skill, they deal twice as much damage to sworn enemies with a regular shot. The "rain of arrows" skill allows them to attack all sworn enemies on the battlefield simultaneously (the damage from the arrows in this case does not depend on the presence of "deadly shot"). The "enchanted arrow" skill allows the hero to apply a specific curse or chaos school spell to the enemy when firing, and this skill can be combined with "rain of arrows."
When "forest cunning" is learned in the education branch (by solving a secret), the critical hit chance against a sworn enemy increases by another 10%. A similar effect is achieved with each upgraded guild of avengers in the cities of the Sylvan faction.
That's how it works.