The Horsefly Fangire, also known as Kaede, is an antagonist in Kamen Rider Kiva.
Kamen Rider Kiva
The Horsefly Fangire was held captive by ex-Wonderful Blue Sky Organization scientist Dr. Kanda in his Evolved Lifeform Research Lab. As part of the doctor's Fangire research, the Horsefly Fangire was forced to consume the life energies of other Fangires. However, the Horsefly Fangire was actually secretly using Kanda to become stronger and, once she had no more need of him, killed him.
After freeing herself, Kaede kidnapped Mio Suzuki to become even more powerful. However, this causes Taiga Nobori to get involved and execute the Fangire for attempting to kill Mio.
A male Horsefly Fangire was later one of the Fangires revived by Bishop. It attacked Keisuke Nago and Megumi Aso but was killed by Nago as Rising Ixa.
Kamen Rider Decade
While Natsumi Hikari was trapped within the changing dimensions during the destruction of the worlds, the Horsefly Fangire was among a group of Fangire which wrecked havoc as this was going on.
In the World of Kiva, the Horsefly Fangire was among the Fangire who fought against the Riders and Undead of the World of Blade when their worlds were merged into the world of the Rider War. The Fangires later help Saga defeat the Oni Riders from the World of Hibiki.
However, once the Fangires are revealed to have allied to Dai-Shocker along with the Undead and they abandon Wataru with their queen marrying Apollo Geist instead. The Horsefly Fangire is later destroyed alongside the remaining Fangire and Undead by Diend's Dimension Shoot.