Seidenki appears to be a small oni. He has light-blue skin with small horns and pointy ears. He has short, wavy purple hair, purple dot eyebrows, and purple eyes. His belly button sticks out right above his puffy orange and teal tiger shorts. Seidenki also dons a maroon-colored sash which is used for carrying around his spiked club.
He creates static electricity.
Seidenki is a little shy and doesn't have much confidence in his electric powers.