Sigma is man that was created by a book. He’s in search of a place to call home. He’s a man that is very easily manipulated. 

He’s in a terrorist organization called “Decay of the Angel,” which includes 5 members, including Sigma. The other members are Fyodor Dostoyevsky, Nikolai Gogol, Bram Stoker, and Ouchi Fukuchi. 

Sigma is the owner and general manager of the Sky Casino. He is very passionate it. His Casino is the most important thing to him.