Masaki Kurusu is the final member of the legendary Four Gods from the VOLTS era. Residing in Babylon City, located at the highest levels of Infinite Castle, he is later revealed to be a spy for Brain Trust, tasked with monitoring the lower levels.
His abilities allow him to manipulate light, enabling him to bypass physical defenses and cause internal damage, earning him the title "Controller of Light" or "Flash Master." Additionally, he can use light to blind his opponents' senses.
In the manga, he is portrayed as Hevn's former lover and a close friend of the GetBackers duo. In the anime, however, he openly allies with Babylon City, kidnapping MakubeX under their orders. It is also revealed that he had been spying on Raitei and VOLTS for Brain Trust while serving as one of the Four Kings.
(Source: Wikipedia, edited)
