Ryubee Sonozaki

The Terror Dopant, also known by his human identity as Ryubee Sonozaki is a major antagonist in Kamen Rider Double. As Ryubee he is the head of the Sonozaki Family and leader of the Museum.

Background
Before his son Raito Sonozaki's death, Ryubee was an archaeologist who bought the grounds his estate was built on after finding deposits of fossils and relics forming the collection in the Futo Museum. It was then he found a point were the planet's consciousness dubbed the "Gaia Memory" and brought his family to see it. However, when his son Raito fell into the "fountain" of the Gaia Memory and died, but was somehow resurrected by the planet's powers, Ryubee began his plan for the Gaia Impact and used the Evil Tail charm he acquired overseas as means to overcome the fear that would go with sacrificing his own family to achieve it. As a result, Ryubee when mad and saw the entire city of Futo is his kingdom and he refuses to let his vision of it be ruined, even by his own wife and children. Sometime before Kamen Rider Double's Dopant cases, the Terror Dopant once fought against Kamen Rider Skull as shown in the Nobody's Perfect music video.

Personality
Ryubee was at first a responsible and caring father figure toward his family but after Ratio died and using the Evil Tail, Ryubee grew mad thinking only about his plans of the Gaia Impact regardless of the dangers on the people of Futo including the Dopants (who he sees them as research specimens) and his own family (appearing to be protective of it while he really has no qualms about using son and youngest daughter). He does not seem to consider the Kamen Riders a threat to his plans, instead using the data off of them as a means to perfect his plans for Wakana before turning his attention to regain Philip and complete his plan to initiate the Gaia Impact. The only living thing that Ryubee appears to care about at all is his cat Mick. When he is defeated and the Gaia Impact somewhat fails he starts to remember who he was and remembered the better times with his family.

Terror Dopant
With the Terror Memory and prototype Gaia Driver, Ryubee can transform into the Terror Dopant (テラー・ドーパント, Terā Dōpanto), who can increase the fear in his victims to maddening levels, he has also shown to use this outside his Dopant form. He could also summon the Terror Field (テラーフィールド, Terā Fīrudo) to burn his victims or teleport himself and others across long distances and project his power into his headdress to create a Barong-like creature familar known as the Terror Dragon (テラードラゴン, Terā Doragon). However this leads the Dopant vulnerable to attacks as he is left powerless.

Part in Story
Ryubee spends most of the series in the Sonozaki Manor rarely having any part in most Dopant crime waves. He appears as the Terror Dopant usually when necessary and involving the Museum affairs. When beginning the Gaia Impact plan he invites his family (mainly Saeko and Shroud) to beg for forgiveness as Wakana will become all-powerful through the Gaia Impact but Saeko refuses and fights against her sister instead and Shroud takes her leave. He then sacrifices Raito (Philip) once more into the Gaia Memory to make his daughter Wakana one with the Earth, he is confronted by both Kamen Riders. While Kamen Rider Accel as the AccelTurbuler destroys his Terror Dragon, Shotaro is able to retrieve Philip's mind and then his body from the aspects of the Gaia Memory in ClayDoll Xtreme to transform into Kamen Rider Double CycloneJoker Xtreme to defeat the Terror Dopant and destroy the Terror Memory, along with most of the Sonozaki estate. With Ryubee's mind still broken from years of planning, he enters the still burning ruins of his home, glad that he finally initiated the Gaia Impact. He dies in the blaze, thinking of the good times he had with his family before he discovered the Gaia Memory.