From Ex illis wiki
|Modify:||Deals Fire damage instead of physical damage and hits reduce Elemental Resistances by 25% over 3 turns.|
Some serjants are more skilful than others with magic. They can bewitch the blade of their swords so it burns their opponent and reduces their resistance to more experimented casters’ burning attacks.
Elemental damage ignores armour, which is a great additional tool to a Serjant’s arsenal.
Furious Blade deals scorching Fire damage, leaving your opponents weak in the face of other attacks such as this one. It uses the Elemental Resistance reduction to deal even greater damage. It is also good to open the way to the Ympes’ Fire Bolt, dealing additional damage.