Shisuku

The Shisuku Family
The Shisuku are a family of Dark Users that Masuyo descended from. They used to live in Council headquarters. As Baku Sen'nin said, they were a relatively normal family. Baku Sen'nin also states that Masuyo may be a descendant from the original sages, so the Shisuku family is a long-lived presence in the Elemental world. Some notable members of this family are below.

Shisuku Xen
In an EleTalk, it was said by Baku Sen'nin that the council was founded by Shisuku Xen. He is two generations behind Masuyo, making him Masuyo's grandfather. However, nothing has been said on this matter in the manga itself. It is also rumored that Xen fought Hoku a long time ago, creating Vista Ridge.

Shisuku Fuuin
Shisuku Fuuin was said to be the most powerful Shisuku. Baku Sen'nin describes that among the rest of his peers, Fuuin was "more akin to a god". He is Masuyo's father. It is revealed by Black that Fuuin led the Unionists, also known as the Army of Darkness, in the First and Second Great Wars. Baku Sen'nin says that Masuyo does have the potential to surpass him. Fuuin's current fate is unknown.

Shisuku Masuyo
Masuyo is a main character in the series. As far as his family goes, he is only in touch with himself at the moment. His younger sister also seems to be a big part of his childhood, but it is unknown whether she is a Shisuku daughter or the daughter of Masuyo's stepmother. See his main page for more information.