Rintaro Shindo is Kamen Rider Blades and The Secondary Rider Of Kamen Rider Saber
Rintaro was born orphaned In Wonder World And Raised by the Sword Of Logos guild. He was trained by the previous Kamen Rider Blades the latter eventually died in battle against Zooous. Rintaro would inherit his master's Seiken and Lion Senki Wonder Ride Book, becoming the second Water Swordsman.
After witnessing Touma Kamiyama, a “Homo Sapien” becoming Kamen Rider Saber, he tracks him down at his bookstore and asks him to hand over the Driver and Sword, fearing that Touma’s newfound great power would become dangerous.
When Touma ultimately decided to help fight against the Megid, Rintaro took him to the Sword of Logos HQ in the North Pole. Chasing after the Ari Megid, Rintaro transformed first to give Touma a demonstration on a Kamen Rider's default powers and abilities.
Rintaro places the Sword of Logos organization and rules above all else, and at first glance, he appears to be serious and difficult to approach. However, he is actually quite down-to-earth and was willing to teach Touma the ins-and-outs of becoming an effective Kamen Rider, though Touma's rather unorthodox methods of fighting often leaves him flabbergasted.
Because of his status as a member within the Sword of Logos, Rintaro has yet to acclimate to Earth. While he is extremely knowledgable about human and Japanese culture in general, he has no actual practical experience in it. This is made apparent when he arrives at Touma's bookstore for the first time while riding a blue lion because he had read that it is rude to enter with his shoes on. He also demonstrates this through his first time winning and holding an instant camera.
As Rintaro was an orphan from an early age where he was literally raised by the Sword of Logos, he sees everyone as if they were his own family. He particularly saw his mentor Kenshin Nagamine as a father, and grew a deep desire for revenge against Zooous for his death. However soon enough, Rintaro realized that revenge isn't an answer. This is shown through him attempting to stop Kento Fukamiya from enacting such revenge on Daichi Kamijo for his father's death. When Kento ultimately perished, Rintaro was struck with guilt for not being strong enough to protect him.
Because the Sword of Logos raised him as an orphan, Rintaro places the organization in high regard. This devotion to the organization ends up being Rintaro's undoing, as it blinds him from any evil the Sword of Logos is involved with, resulting in his refusal to believing or hearing out any claims of such corruption.
He has a keen eye for good food, especially after his love for sweets was discovered