For those who are interested the "Red Demon guy" is Momotaros. He is an Imagin from the 2007 Kamen Rider series,
Kamen Rider Den-O which is the seventeenth installment in the Kamen Rider series.
Kamen Rider Den-O gets his powers from four imagins, Momotaros is the one who gives him his fighting/sword form. Momotaro is a popular hero from Japanese folklore and is translated as peach boy.
https://en.wikipedia.org/wiki/Momotaro
Here is the Wikipedia information as a overview
Sword Form
Japanese legend: Momotar?
Imagin: Momotaros
Rider height: 190cm
Rider weight: 87kg
Ability perimeters
Punching power: 5t
Kicking power: 7t
Maximum jump height: 35m
Maximum running speed: 100m/5.2s
Sword Form (??????? S?do F?mu?) is Kamen Rider Den-O's first form. When in Sword Form, he uses the DenGasher as a standard sword-style weapon. Sword Form is the most balanced of all his forms. However, Sword Form is unable to operate underwater. This is the more commonly used Den-O form, possibly because of Momotaros' prominence among the other Imagin. Every so often, Momotaros will develop a new Hissatsu Attack (??? Hissatsu Waza?) that he uses to finish off Imagin, and has developed Parts 1, 2, 2' (2-dash), 3, 5 and the other-Imagin-assisted Final Version, although the attacks hardly differ from one another (Final Version uses the energy of the other Taros, Sieg and Zeronos, making it the only exception). The eyes on the "mask" of Sword Form resemble two halves of a peach, the fruit associated with the story of Momotar?, the Peach Boy.
When not in action he hangs out in the dining car of the Den-liner drinking Gold Gentlemen Coffee
Momotaros (????? Momotarosu?) is the hot-headed Imagin that first possesses Ryotaro without knowing that he is a Singularity Point. He decides that it is more fun to fight other Imagin rather than grant a wish such that he can destroy history to his liking. He is also the subject of most of Hana's abuse, getting easily knocked out by one of her punches. He also demands that he is treated better than the other Imagin as he contracted Ryotaro first. As Den-O, he happily fights other Imagin using his swordsmanship as Sword Form, leads the other Taros in Climax Form, and his power is tapped in the DenKamen Sword's MomoSword mode.