Orochi seal

The Orochi seal is an artifact present in The King of Fighters (series).

1800 Years Ago
This artifact contains Orochi's soul and his eight servants. During the ancient times, a being was born from the Earth itself, named Orochi. A divine being who calls itself "Gaia's Will", manifested through floating emotions and substances of nature, and became the equalizing force between humans and nature. Orochi was nature's guardian and was granted with many of its powers. It gained followers to its cause and eventually formed a clan. The eight strongest warriors of that clan would go on to be known as the Hakkesshu. As the mankind began to grow in numbers, however, the natural balance began to crumble.

660 Years Ago
Orochi could no longer tolerate the destruction as a byproduct of human progression and wanted to completely wipe humanity from existence. Orochi decided to use the powers gained from nature to reign havoc on humanity. The Hakkeshu and the human race waged war until the Kusanagi, Yata, and the Yasakani defeated it with three mystical treasures; the Kusanagi Sword, the Yasakani Jewel and the Yata Mirror. The Hakkeshu and Orochi were defeated and sealed. Though kept in a suspended state, Orochi continues to feel that mankind pollutes the world.

Protectors
The protectors of the seal are the three clans that sealed Orochi 660 years ago: the Kusanagi Clan, the Yagami Clan (formelry known as Yasakani Clan) and the Yata Clan (A.K.A. the Kagura Clan).