The Midnight Sun King Yaiba (白夜王ヤイバ) is a character in the anime and manga series Battle Spirits Sword Eyes.
He has black, spiked-up hair and dark-colored eyes. He wears a long, white and yellow button-down top, over white pants, with a black belt. He wears a black cape, which is green on the inside, and has gold plating with tassels on the shoulders.
He appears to be cruel for no reason and thinks light only exist to obey the Sword Eyes of Darkness. He wants power to surpass the gods and rule the world.
Yaiba is the white Sword Eyes of Darkness. He is Tsurugi's older brother. He was born on the day of the midnight sun, which is a holiday. Yaiba made himself the king of Atlantia.
He is trying to gather the 12 Sword Eyes and Sword Braves, but claims that isn't all he needs for his plan.
Tsurugi came to Atlantia to challenge him, hoping to find information on his mother's whereabouts. Yaiba accepted, on the terms that if he won, he could have Tsurugi's Sword Brave, and easily won him. He was disappointed by how weak Tsurugi was. He failed to obtain the red Sword Eyes and Brave, because Bringer saved Tsurugi.
Yaiba began to spread Stinger armies around each country of Legendia, stating that it would bring ease to the people, and prevent the Sword Eyes of Light from rioting.