Soichi Isurugi

is the father of Misora Isurugi, owner of Nascita, and former astronaut who was possessed by the alien and transformed into and later . After Evolto's defeat and the creation of the new world, Soichi returned to his normal life without any of his previous memories.
==History==
===Background===
Soichi Isurugi is the father of Misora Isurugi and a former astronaut working with the Kiwami Project. Ten years ago, Soichi was on a manned exploration on Mars and discovering the Pandora Box in the ruins. However, as he touched the relic, the extraterrestrial lifeform Evolto would take over his body and returned to Earth. To create the sixty Fullbottles from the Pandora Box based on Soichi memories, Evolto asks the man for thirty things he liked to create Biotic Bottles and odd objects to create the Abiotic Bottles.
Upon arriving on Earth, Evolto used Soichi's body to trigger the Pandora Box and raise the Pandora Tower. However, his attempt failed as Vernage also found her way to Earth and took hold of Misora's body to remove the essence of the Fullbottles, causing the Sky Wall to rise instead. After being medically diagnosed as being "psychologically insane", Soichi was arrested and placed in a mental hospital, in which Misora was also admitted into as well. Several months later, Evolto escaped from the mental hospital and took residence in Touto where he opened up a café called Nascita there.
Evolto continued to possess Soichi's body as he led Faust as Blood Stalk and posed as Sento Kiryu's mentor figure as he indoctrinated him to become Kamen Rider Build.
===Release from Evolto===
Sometime after Vernage made her presence, Soichi's consciousness was able to reemerge and trying to resist Evolto's hold over him. Soichi questioned Evolto's intentions before Evolto regained his control. He told Soichi not to do that again and to keep silent and watch as he transformed into Blood Stalk.
When Evolto initiated "Phase 2" of his ultimate plan and possessed Ryuga Banjo, he had finally separate from Soichi Isurugi's body. Soichi was left unconscious and taken to a hospital by Sawa Takigawa and Kazumi Sawatari. After the Evol-Trigger was repaired and regained his Black Hole form, Evolto would later assume Soichi's appearance.
===New World===
After Sento defeats Evolto for good, the new world had been successfully created. This new world version of Soichi now works at Nascita with his daughter. He's shown to actually be able to make a good cup of coffee, as proven by Sento, unlike Evolto's possession of him in the old world. Soichi mistakes Sento for Taro Satou, of the band Tsunagizu, and asks for his autograph. 
During the events of Build NEW WORLD: Kamen Rider Cross-Z, Misora mentions that her memories from the old world have returned but Soichi doesn't remember anything about the old world, since he was not being experimented on with Nebula Gas and his abilities was a result of Evolto taking over his body.
==Personality==
Ten years ago, Soichi was said to be a kind and caring person, as shown when he reads to his young daughter Misora Isurugi, remembering all the things she liked. According to Sawa's investigation of him, Soichi was also described to be someone who was friendly and had a strong sense of justice. However when he returned to Earth with Pandora's Box, he was possessed by Evolto. During his possession, Soichi was constantly struggling for control of his own body, although his attempts were in vain.
It's also implied that while Evolto is possessing Soichi, he would emulate Soichi's original personality.
==Forms==
==Equipment==
===Devices===
*Transteam Gun - Blood Stalk's transformation device and personal weapon. Evol inherits it as his personal weapon
*Fullbottles - Blood Stalk's transformation trinkets. Used by Evol to summon weapons and perform finishers.
*Evol-Driver - Evol's transformation device
*Evolbottles - Evol's transformation trinkets
*Evol Trigger - Evol's upgrade device for Black Hole form
===Weapons===
*Steam Blade - Blood Stalk's standard sidearm weapon. Can combine with the Transteam Gun to form the Steam Rifle. Continued to be used by Evol.
*Drill Crusher - Evol's personal weapon in Rabbit Form
*Hawk Gatlinger - Evol's weapon granted by the Gatling Fullbottle
==Behind the Scenes==
===Portrayal===
Soichi is portrayed by . As Evolto, his other voice was voiced by , who previously voiced Namakelder in Happiness Charge Pretty Cure!. As Blood Stalk and Kamen Rider Evol, his suit actor is .
===Etymology===
The katakana in his name is usually translated as "Stark". The name "Stark" in Blood Stark can also be "Stalk" and "Stalker".
==Notes==
*As a hint to Stalk's true identity as Soichi, the collar on Blood Stalk's suit was modeled after the collar of a space suit.http://blog.livedoor.jp/shfiguarts/archives/1069025804.html
==Appearances==
==References==
==Navigation==
Category:Build Characters
Category:Cobra Monsters
Category:Good turns evil
Category:Allies
Category:Villains
Category:Debatable Riders
Category:Evil turns good