Seimei

was the founder of Takumi Village, known for creating weapons for other shinobi villages.

Personality
During his short appearance, Seimei acted calm, cold and aloof, believing his opponents efforts to be in vain against his power, openly laughing at them, showing his arrogance and pride. It was only when his opponents managed to successfully strike back or elude his attacks that Seimei lost his cool. Seimei was also credited by Gaara as believing ninja to be nothing but weapons. As the founder of Takumi Village, he was also extremely loyal to it. He also seemed to be of a cruel and selfish nature as when Gaara was in extreme pain he only cared about his revival and infinite chakra supply.

Abilities
Seimei was considered a great and powerful shinobi to the point that the villagers of Takumi considered him to be the ultimate weapon. His mastery of weapons, along with the ability to skilfully utilise both Fire Release and Wind Release nature transformations, certainly testified to his power. Seimei also showed quick analytical and deduction skills when he merely glanced at the cage imprisoning Gaara to understand what had transpired before his resurrection.

Bukijutsu
Seimei has shown being capable of combining the Infinite Armour, Weaknessless Soaring Shortswords, Garian Sword, and Hōki's Fire Sword, to truly become the "Ultimate Weapon". His mastery over the weaponry and armour of the Four Celestial Symbols Men was great enough for him to be able to use their abilities telekinetically and without any necessary movement. In addition to combining the weapons, Seimei was also given the ability to float on a globe of chakra. The globes seem to be the green orbs in the three swords as they disappeared after the orbs appeared.

Ultimate Weapon Arc
Hōki, Kujaku, Ryūgan, and Suiko removed his body from his crypt with the power of the Shukaku. Hōki then sacrificed his body to revive Seimei. Once the preparations were complete, Seimei used the weapons from his dead comrades to create the "ultimate body". He was later killed by Gaara. Though Seimei was difficult to kill, the fight was essentially over when he was hit by the Ultimately Hard Absolute Attack: Spear of Shukaku in his chest, demolishing the so-called "indestructible" armour. Gaara wasn't taking any chances, and followed up with a Sand Waterfall Imperial Funeral in the pit of sand he had created using minerals from bedrock, killing both Hōki and Seimei.

Trivia

 * Seimei's name is likely taken from the legendary onmyoji Abe no Seimei. Strangely, the Seimei of legend was supposedly born from Kuzunoha, a kitsune, while the Naruto universe's Seimei was revived through the chakra of Shukaku, a giant tanuki (a species known for its rivalry against the kitsune in folklore).

Quotes

 * (To Gaara) "Pathetic, shinobi have no need for emotions, those that kill their emotions become more powerful, and that power is the only justice. You're already finished."

Seimei