"What!? You can actually create that thing!?" Hermes, usually lighthearted and casual about everything, blurted out in alarm.
He recalled the distant past, during the war between Poseidon and Atlantis. This cannon was one of the things the gods feared the most. In that conflict, the cannon effortlessly slew Abysmos, Poseidon's favorite pet, with a single shot. It also came dangerously close to killing Poseidon himself. Fortunately, the power charged during the shot was not potent enough, sparing Poseidon's life.
This incident is one of the reasons why the Olympian gods contemplated eradicating humanity and creating a new species subservient to them. Some gods, however, chose to stand with humans against the Olympian gods, and Hermes was one of them.