[ Project: 'Vermillion Plumes' is set in an alternative timeline when vampires co-existed with humans in the late 1940s fighting an alternative WWII. ]
..VOS-2D was an advanced prototype fighter developed for the Imperial Navy.
Its radical wing design gave it jaw-dropping agility / low-speed performance but also made it almost impractical to mass-produce.
Only small numbers were built and issued to special fighter units.