Rudra Nam Ul Nasca

Rudra Nam Ul Nasca (ルドラ・ナム・ウル・ナスカ) was the founder and emperor of the Eastern Empire.

At the climax of Tempest's war with the Eastern Empire, Rudra's life fully came to an end when the last remnants of his soul departed his body, clinging to Velgrynd's "other body" as she was banished to the end of time and space by Feldway.

The "other body" of Velgrynd that Rimuru captured went on to collect all the pieces of Rudra's fragmented soul across worlds and united them in its complete state within Masayuki.

Appearance
Rudra had medium length blonde hair, blue eyes and the looks of a handsome young man. He was described by Yuuki to have eyes that seem to see through everything. In illustrations, Rudra is seen wearing black eastern clothing with gold ornaments.

Personality
Rudra was an absolutist, a cold-hearted man that advocated the principle of "might jakes right" in his empire. He was always keen to add more powerful individuals to his military, even going as far as sacrificing an army of millions just acquire a few stronger pieces.

In the past, he once dreamed of a unified world where everyone could live happily, but after experiencing many tragedies, and losing his mind from reincarnating so much, his values erroded away, giving way to an empty husk of a man obsessed solely with winning his game against Guy through any means.

Background
Rudra was originally the prince of the small kingdom of Nasca, being the older brother to Lucia Nasca, its princess. He was born with great talent and received the blessing of an Elemental of Light, becoming the first Chosen Hero, or more aptly put, "Hero of the Beginning". He was also Veldanava's disciple. As the crystallization of his vow to unify the world, and the thoughts of his friends who responded to to that vow, he awakened to the Ultimate Skill Uriel, which was later exchanged with Veldanava's Ultimate Skill Michael, in a show of support for Rudra's dream.

Rudra wanted to convince Veldanava, who lost his immortality and became tied to a lifespan, who worried about the future of the world, that it would be in good hands. He also wanted to bring happiness to his sister, who was pregnant with Veldanava's child. Finding Rudra's dream unrealistic, Veldanava sent him to the Lord of Darkness, Guy Crimson, to reason with him.

Rudra eventually befriended Guy and became close friends with him, with them having sparred numerous times as rivals. He tried to convince Guy that humanity is capable of understanding each other, that there was no need for him to keep killing. Guy was not easily convinced, and thought his wish was naive and would never come to fruition.

Aware of Guy's unchanging stance, his position as mediator, and Veldanava's condition, Rudra proposed a game where they competed for world domination. The only rule was they couldn't directly compete, only their pawns. In other words, so long as Guy and Rudra did not confront each other directly, they could do whatever they wanted. The world was their board, monsters and humans were their pawns. At first, Guy’s pawns were monsters and majin, while Rudra’s were a portion of humanity. They had kept up this game, switching their pieces over the centuries.

As time passed in their millennia-long game, Rudra experienced countless tragedies. While on an expedition, a terrorist attack took place within the Nasca Kingdom, claiming the lives of Veldanava and Lucia. Despite being heartbroken over their loss, he continued his game with Guy, claiming it was the only thing he had left, and carried on out of a sense of duty for all the sacrifices made. With each reincarnation, his soul wore out; his holy powers depleted and he lost his qualification as a hero. His mind got taken over by Michael, with only the slight remnants remaining influencing the latter to follow the game to the end. Ultimately, Rudra lost his original ideals and became obsessed with winning the game by any means

Trivia

 * Rudra's character design is possibly inspired of Fate's Gilgamesh, as both share the same palette and being "First Hero".