Chikara Saionji is an ally of the Gamma and a major antagonist in Kamen Rider Ghost. He seeks to gather the Eyecons so he may use them to become ruler of the world.
In 2005, Chikara was a partner of Ryu Tenkuji in paranormal research. He secretly conducted an experiment that caused Kanon and Makoto Fukami to be sucked into a Gamma Hole. Ryu and Kenjiro Igarashi soon arrived but they were too late to stop Saionji from escaping.
Chikara later allied with Alain, who promised to help him find the 15 Luminary Eyecons in exchange for his help with the Demia Project.
Saionji summoned a pair of Eyecons that turned into Gamma. He provided the two a Yari and a Katana to allow them to become the Empowered Gamma Yari Gamma and Katana Gamma. After both were destroyed by Kamen Rider Ghost, Alain stated to him that an obstacle to their agenda had emerged.
Saionji was later able to steal the Eyecons while Kamen Rider Ghost and Specter were distracted fighting Jabel. He then went to the Daitenku Temple and activated Monolith so he could ask it and the Ghost Eyecons to make him the ruler of the world. However, the Eyecons rejected his demands and dissolved him into Monolith, presumably killing him.