Mjölnir

Mjölnir costs 1 and 2  at Sho'guul's lair.

This relic deals lightning damage whenever it hits an enemy, this works with. This item was buffed in the 1.1.0 update to do AOE damage on hitting an enemy, and there is now no timer on the relic. this was shown by the developers on twitter before the update. However it was also nerfed, as the damage dealt is now less that it was before.

Trivia

 * This item is also the logo for Thorium Entertainment
 * It is a reference to Marvel/Norse mythology as a weapon wielded by Thor the god of thunder.