Sakanoue no Tamuramaro

About
Sakanoue no Tamuramaro was a general loyal to Fujiwara Ishimaru, the Emperor of JAPAN and most of humanity a bit over 2 millennia before Rance's time.

Fujiwara bestowed upon Tamuramaro the mission of subjugating the Northern tribes in JAPAN and the title of Seiitai Shogun, or Shogun Conqueror of the Barbarians.

Barbarians are likely a reference to the Youkai, though this is very tenuous as it never states this and Dokuganryuu Masamune only created the modern Youkai Kingdom in Ezo a decade or two before the events of Sengoku Rance. Nevertheless, there was a Youkai Kingdom of some sort made of the followers of First Youkai King, Kurobe that was located in remote mountains, likely located in the same place.

Fujiwara is known to have fought and defeated Kurobe during his 20s on adventures that he undertook alone before becoming the emperor. So Tamuramaro probably was sent to subjugate the north at the very end of Fujiwara's reign when Fujiwara and his followers were pushed back into JAPAN by Xavier's demon army, perhaps to keep the peace in the North where remnant youkai who did not follow Kurobe might have been causing trouble.

Regardless of why exactly he was sent north to subjugate the barbarians, Tamuramaro never completed his mission. He became lost in Saitama and Oshu, and his men died. However, Tamuramaro himself kept on as a wandering being of some sort, perhaps under some kind of curse or compulsion.

Even to the present era, he seemed to be reliving his ancient quest to conquer the barbarians and attacks those who appear before him, misunderstanding them to be his ancient enemy.

With him, he carries the Seal of Approval, an item that gives the bearer the duty to protect the Northern regions of JAPAN. Rance defeats him in order to gain a reason to declare war on the Youkai Kingdom of Masamune.