MysteriousVaporeon is a member of Route 50 and a real-life friend of AngelicUmbreon. He is a cybornetic Vaporeon with a tail that can transform into a scythe, a rail gun, a bazooka, and various other weapons. He has a known hatred for My Little Pony. He has special weapon-crafting powers, and has an affinity for heavy firearms.
Prior to his incident, MV was an ordinary Vaporeon with a Link hat. However, his tail and other parts of his body were replaced with robotic parts after a run-in with the Eeveebot. He wears a steel half-mask to cover an evil scar on his face, as well as a fedora.
MV's mechanical tail packs a punch when swung, and can also shift into a variety of weapons, including a scythe, a minigun, rocket launchers, a laser cannon, and a deadly scorpion tail. His real-life cat, Wilson, occasionally appears as his sidekick, or as a more powerful machine gun.
Due to heavy fighting, MV frequently has organic body parts replaced with more robotic parts, though he is usually portrayed only with the half-mask and the mechanical tail. Nonetheless, MysteriousVaporeon predicts that by the year 2020, his body will have become completely replaced by artificial parts due to accumulated injuries, rendering him as a complete robot.
Maestra cast a curse on MV that will cause crows to attack him wherever he goes.
Some time in mid-late 2012, MysteriousVaporeon was confronted by Kyubey, who he was deeply suspicious of even before watching Puella Magi Madoka Magica. After attempting to slay Kyubey, MV was tricked into signed a magical girl contract that transformed him into "FeMV." MV maintains ambiguity whether FeMV is a complete genderswap or merely crossdressing.
Because MysteriousVaporeon usually portrayed himself as an edgy, all-powerful, destructive warrior up until then, the sheer cuteness of FeMV became an instant hit on Route 50.
After watching PMMM, MysteriousVaporeon reported that FeMV had become a witch. Basscannon later created a genderswap of herself, Angelo, to accompany FeMV.