Sento Kiryu

Sento Kiryu (桐生 戦兎 Kiryū Sento) is a genius theoretical physicist who experiments with Fullbottles to further enhance his abilities as Kamen Rider Build (仮面ライダービルド Kamen Raidā Birudo) to fight against the evil Smash organisms. 
He makes his debut in the upcoming DZ2K19 and is one of the main characters.
== Personality ==
Sento's outstanding traits are his intellect, narcissism, and sense of justice. A genius by all standards, Sento has repeatedly displayed advanced knowledge in physics, mathematics, chemistry, engineering, and cryptography.
Sento's polymathism is accompanied by an inflated ego and sharp tongue: he likes to praise himself for his works, and often mocks Ryuga for his comparatively lower intelligence. Sento often relies on his own skills to solve problems and never expects sudden assistance from others, so when it happens, he tends to either be surprised or turns them down. Also, Sento can be easily caught off guard when he accomplishes anything or witnesses something unexpected and new which excites him, because of his reliance on his intellect. In this state, he is vulnerable to any surprise attacks.
Sento can be easily attracted to anything that is mysterious and interesting, such as new innovations and anything that brings him closer to uncovering his past, and will relentlessly pursue it. This will continue until either he reaches a conclusion or someone forcibly stops him during progress. When Sento gets excited (usually due to a discovery or breakthrough), a part of his hair sticks up.
Sento's greatest trait is his sense of justice. A firm pacifist, he believes that science should be used for the sake of humanity, and harshly opposes using it for war. His selflessness and sense of duty causes him to try and shoulder the burden alone rather than involve others, whether he can carry that burden or not. This altruism intensifies the guilt he feels for his role in creating the Smash and escalating the war. While generally calm and composed, Sento is prone to making poor judgement during emotional turmoil.
== DZ2K19 ==
Overall: 93
Rival: Yue Ying
Reason: Like Sento, Yue Ying's also an inventor.
Taking place during Episode 11 of Kamen Rider Build, Sento receives word that the Mishima Zaibatsu has been attacking multiple worlds using the Marker.
Due to the Mishima Zaibatsu, led by Nicole Brennan, his world was under attack by the Necromorphs. With most of the civilians killed, Sento decides to turn the cafe into a shelter. When Isaac and Xianying were under attack by the Brute, Sento jumps into the fray to protect both of them. He transformed into Kamen Rider Build and, though the Brute was tough, easily defeated the Brute. He soon stole the essence of the Slasher Necromorph after he killed it in front of Misora, who was under attack by one. With the essence in hand, Sento worked on curing the dementia stemming from the essence, unaware that it was caused by the Marker.
Sento later joins Isaac and Xianying during their search for Shizuka Hio. Isaac was hesitant when Shizuka offered her services in exchange for Xianying turning into a vampire, but Sento firmly agrees with what Shizuka said. But it all went downhill when Zero's parents arrived. In a flash, Xianying gets attacked by the Pureblood, Isaac protecting young Zero and Zero's parents got killed. Realizing that Shizuka caused this, Sento jumps to Xianying's aid, trying to keep her alive as the best as he can.
This made Sento realize that Xianying wanted to turn because she wanted to provide a better future. This reinvigorated Sento's spirit. He decided to join Xianying's team.
Later in the story, Sento reveals that he's finished with it and decides to give it a go. Despite Isaac's protests, Sento transforms into Kamen Rider Build with the Necromorph Diamond form. To Isaac's surprise, Sento had got rid of the dementia from the Necromorph, meaning that he can transform into one without suffering from what both Isaac and Xianying had.
In the final battle, Sento, along with Isaac, Xianying, Chang, Monster Hunter, and Ria Iwamura, confronts Nicole.
In Sento's ending, he's seen with Ryuga. And though Sento managed to extract the dementia from Xianying, it was too late as the latter was singing a lullaby. Feeling remorseful, Sento decides to help Xianying in any way that he can.
== Kamen Rider Fighters ==
Sento, as Kamen Rider Build, is one of the playable characters in Kamen Rider Fighters by Bandai Namco. He is also one of the main characters.
== Kamen Rider Build ==
As Kamen Rider Build, he can use whatever he can see to merge into one.
== Warriors Orochi 4 ==
Sento appears at the Battle of Taoyang. He saves Guan Yinping, Yoshitsugu Otani and Fu Xi from Orochi's forces. 
After the Battle, he joins the newly formed Coalition and gives Yue Ying a copy of his Build Driver. 
== Trivia ==
* Sento shares his English VA, who voices himself in the DZ2K series.
* According to BasicallyIDOWRK, he had no idea about Kamen Rider. He said that it was sheer luck that he somehow managed to sound like him.