Shouki

Kamen Rider Victory Demon is one of the many Oni Kamen Riders in the fanfictional series Kamen Rider: Echo Demon.

Shuki
Danki is an Oni who is partnered with Warm Air Demon. Like most of the Oni Kamen Riders, it's unknown if he has a human form &/or a human name.

Transformation Demon Flute
A flute whistle transformation device.

Sound Attack Cry - Bundled Wind
A trumpet buckle.

Sound Attack Tube - Typhoon
A trumpet Sound Attack weapon.