| A blade somehow crafted from pure electricity. Striking an enemy with it occasionally unleashes powerful arcs of lightning.
These may arc to other adjacent creatures, or back to the wielder, before eventually grounding out. It deals reduced damage when arcing to the wielder, and bypasses any armour the target may have.
Compared to Static Discharge, the arcs from this weapon do more damage and arc more often to adjacent monsters due to the high spellpower used. The Arc Blade has damage output that's a bit higher than a fully enchanted demon blade of electrocution, hence it's a strong weapon the entire game versus monsters without electricity resistance. Against crowds, the discharge damage tends to spreads out, a useful effect if you can fight foes in a bottleneck.
Against electricity-resistant targets, however, this weapon is far less useful. Versus electricity immune monsters, it's no better than a +8 rapier that happens to grant rElec. Carrying an alternate weapon is strongly advised, as electricity resistance is common later on.
Additionally this weapon is not good to use near allies, since those might get hit by its arcs. However it will warn you if your attack could harm one of your allies.