The Samurai Lord is the first wielder of the mystical sword, an emperor, and the first human to defeat Aku. He is also Jack's father.
The Samurai Lord had lived in a Feudal Japan. He wanted to destroy the being who caused chaos known to him at the time the black mass but made it worse and his name was given as Aku. Odin's horse helped the emperor go to a mountain where Odin, Ra and Vishnu made a sword out of his own spirit of purity.
Jack's own father looks like an older version of his son. He has his son's rectangular head, hair style (his hair is gray but black in his younger years), and eyes, & he has a mustache (color's are the same as hair that differ from age), but there are subtle differences, like his father has a more light hearted expression compared to his son's stern look like any old samurai warrior.
Though he had alot of little screen time, Jack's father's personality is very similar to his son in every way. He is a kind, modest,nice and wise man who was loved by his people, especially his wife and son, who were the most important things to him.
Before Jack was born, his father had been pulled into the great battle against Aku, a shape-shifting sorcerer. Despite having a powerful army, he didn't stand a chance against the sorcerer and his forces were destroyed. Just as all hope seemed lost, the gods Odin, Ra, and Vishnu bestowed Jack's father a mystical sword that could harm only Aku, but could only be wielded by one pure of heart. The sword accepted him and with it, Jack's father defeated Aku and brought peace to the land just as his baby son was born. And many years later, with Jack now as a young child, Aku awakened and very enraged by his defeat had finally awakened from his prison and attacked the land once again, but this time he captured Jack's father before he could retrieve his sword. Before he was taken away, Jack's father asked his wife to take care their child and help him become the next hero who would defeat Aku; this time forever. After years of training, Jack soon found his father, now a decrepit and also weakened old man. He told his son that the sword he wields is the only true tool who could defeat aku and it is only as powerful as the one who wields it.