Personality: 

Eccentric and big-headed, Sōichirō's real motives remained a mystery to everyone who knew him. After the loss of his parents, he developed a dangerous philosophy about humans and how they work. Although few could tell because of his bizarre persona.

He would often introduce himself with an odd title, usually to do with being the 'patron Saint of children'. Cruelly, Sōichirō would treat Es like a doll, not caring for her individual self, only viewing her as a machine to be used and thrown away. When he found out that Touya is a clone created from the Original Grimoire, although he hid it from him, no longer saw him as a living person and began to view him as nothing more then a "corpse".

Although he never believed himself to be one, Soichiro is also a hypocrite of his own beliefs. While he states everything he does is for the sake of humanity, he shows a lack of empathy for them, as he sacrificed and killed the Unions he was supposed to cure to harvest their crystals, forced Mei into working for using her father's condition, guilted Touya into helping him, showed no concern for Akira after removing his own crystal, and savagely beating Hinata for ruining his plans.