Black Barrel

A black rifle of Gun God. It is entirely made of substance opposing Ether, so it's a natural enemy of Ether users. However, since all life forms of this world has adapted to Ether's influence, thus practically nothing is capable of wielding Black Barrle. As a God-killing gun, target's power, or in other words, the amount of Ether the target controls, exponentially relate to the gun's lethality.

...now only the rare pure life form, those who failed to evolve, may touch this gun without influence.