Yami (常闇ノ皇 Tokoyami no Sumeragi "Emperor of Everlasting Darkness") is the main antagonist of Ōkami, and considered Amaterasu's archenemy. He is granted that it lives up to that title, since Yami is not exactly like previous bosses.
It is only near the end that Amaterasu learns about Yami, and how it and an army of demons slaughtered many innocent Celestials on the Ark of Yamato. It is believed that from this Ark all evil beings come from, since it was the Ark in which evil beings came upon in the first place. It is said that there was only one person who managed to escape the slaughter.
Yami appears as a large mechanical sphere covered in arcane markings and cloaked in darkness, but is actually a small, fetal and primitive looking fish creature enclosed within, and operating the machine. It is noted that he has markings which are similar to Amaterasu's, but blue rather than red. The orb can morph into a variety of positions to attack.
- Yami (闇) translates to darkness, get dark, gloom and disorder.
- When Yami enters its last form, the solar eclipse on the Day of Darkness completes itself and the sun is covered by the moon. This may symbolize Yami defeating Amaterasu. Additionally, Amaterasu seems weakest at this time, whereas Yami is strongest.
- Despite Yami's links to the Moon, Crescent is very effective against it because it summons Nagi (possibly because it gives moonlight, rather than block the sun as an eclipse does).
- Yami was the first woman in Vedic beliefs. She was a child of the Sun god and had a second name, YāmīnĪ, which means 'night'.
- In Tibetian beliefs, Yami is the goddess of death and rules the female spirits of the underworld
- Like Amaterasu, Yami is not able to speak. However, it appears to be capable of expressing rage.
- Yami appears as the primary antagonist in Tatsunoko vs. Capcom: Ultimate All-Stars as the one responsible to merge the universes of Capcom and Tatsunoko with the real world.
- On the teleportation zone in the Ark of Yamato there are markings of Yami's final form. Also, in the concept art for the Ark, more of these markings are present.