One legend about Sima Yi is that he could turn his head 180° around on his neck to look backwards without turning his body. This characteristic was called "the turning-back of the wolf" (狼顧) supposedly based on the fact that wolves are cautious and aware of everything going on around them as though they had eyes in the back of their heads. It is said that Cao Cao heard this rumor and wanted to test it for himself. According to the legend, he came up behind Sima Yi and called out his name, and indeed his head did turn completely around. According to the Book of Jin, when Cao Cao saw this he grew cautious of Sima Yi, saying "This man is hiding great ambition". Cao Pi would later say of Sima Yi "This man probably has no intention of ending his life as a mere servant".

Later, his grandson, Sima Yan, become a founder of Jin Dynasty and put an end to The Three Kingdom era.

Short Story, manga version:

The magnificent machinator. The talented strategist of Giga. He has been looking into anicient literature and legends. He suspects that turbulent times will come with the appearance of the person who holds the Ryuuteiken. As a general, his abilities could be on par with Sousou and his dubious personal actions make Sousou keep a close eye on him. He is behind the strategy in the Kurou Fortress battle.

According to the dates in the real Chinese literature, Sima Yi is actually 12 years old during the Battle of Hulao Pass which is the battle which the Battle of Kurou Fortress is based on.

In the Red Cliff battle, together with Houtou and Kakuka betrayed Sousou in order to realize the final chapter of the G Chronicles "Apocalypse". They fire the Shinkahihou to the sky aimming to engulf Mirisha in a sea of flames. After realizing "Apocalypse", they left for the Red Cliff.

Weapon: Shirogane no Kiba(銀の牙) + Kouyokusen(紅翼扇) -> Gayoku no Taiken(牙翼の大剣)