Gentoku Himuro

Gentoku Himuro (氷室 幻徳) is the head of the Touto Institute of Advanced Matter Physics. He is also an aide to the Prime Minister of Touto, who is in reality his father, Taizan Himuro. It was later revealed that he is Night Rogue (ナイトローグ), informally known simply as the Bat Man (蝙蝠男), one of the main villains in Kamen Rider Build. He is a mysterious masked figure that is present during Faust's experiments that turn victims into Smash, including the one from Sento Kiryu's memories.

Character History
Gentoku was in the audience of the return ceremony when the Skywall was raised. Within a decade of the disaster, he became an aide to the Prime Minister of Touto, overseeing research of Pandora Box. He later watches over the human experimentation it conducts and appears in Sento Kiryu's mostly forgotten memories from before his escape, sitting atop a throne. According to Gentoku himself, the reason behind these experimentations is to accomplish one of Faust's objectives: to create the "Ultimate Lifeform."

Gentoku was seen possessing the Rocket Fullbottle.

Personality
Gentoku is a composed and generally calm man, rarely changing his tone of voice unless agitated. Underneath his cool exterior, he is a man with questionable morals at best: he flirted with a journalist, and referred to Ryuga and Kamen Rider Build as toys, as well as his fiery temper whenever he commands his soldiers.

It is likely that some of his negative personality traits are a result of his exposure to Pandora Box during the Skywall disaster.

As Night Rogue, he is very malicious. Seeing innocent people as mere guinea pigs, he doesn't hesitate to experiment on them, even when fully knowing that his subjects would be too weak to survive.

Forms
"Bat! Mistmatch! Bat...Ba-Bat... Fire!"

- Transformation announcement

Ability Perimeters:
 * Height: 197.5 cm.
 * Weight: 103.0 kg.
 * Punching power: 17.2 t.
 * Kicking power: 20.5 t.
 * Maximum jump height: 49.0 m.
 * Maximum running speed: 100 m. per 4.1 sec.

Like Blood Stalk, Night Rogue's form is accessed with the Transteam Gun and the Bat Fullbottle.

Night Rogue seems to possess a degree of steam manipulation as he can turn himself into steam to quickly travel long distances or to summon his Steam Blade. Night Rouge is also shown to be able to fly as well as stand upside down by using his feet to somehow cling to ceilings like a real bat. He can also execute an electrified Rider Punch-esque attack where his fist glows blue with electric energy and hits the target.

Unlike Build, Night Rogue's Ability Perimeters are not spread out between his arms and legs. While Night Rogue gets power from only one Fullbottle, he's much stronger than Build's Trial Forms and his stats even surpass some of Build's Best Matches.

Devices

 * Transteam Gun - Transformation device and personal weapon.
 * Full Bottles - Transformation trinkets.

Weapons

 * Steam Blade - Standard sidearm weapon. Can combine with the Transteam Gun to form the Steam Rifle.

Portrayal
Gentoku is portrayed by Kensei Mikami (水上 剣星). As Night Rogue, his suit actor is Jun Watanabe (渡辺淳), who played Secondary Riders since Kamen Rider Drive.

Etymology
Night Rogue's name is a loose play on English words "Nitro" and "Rogue".