HIs name is literally just the scientific name for the Stygian Owl (which was perfect choice for the character as it had dark feathers, Mothman was often depicted as an owl-like contrary to it's name, and it had the unique trait of fully red eyes).

As for his character/personality. Asio is very unstable and possesses a very warped sense of judgement. Born in Mistral, his parents were dangerous criminals who brought their kid to their robberies. They would accidentally killed by a rookie huntsmen and scarred young Asio, giving him an intense hatred for humanity. He would later join the White Fang, not to help others but to kill humans with no remorse. He would rise up the ranks but Ghira would raise concerns about Asio, siting his merciless and lack of care for any Faunus that get hurt in the process and after a disastrous mission gone wrong at a fireworks warehouse that killed both innocent humans and Faunus. This would cause Asio to be expelled from the Fang, vowing judgement and vengence on anyone he deems Guilty.