Sayo

Sayo (小夜) is an original character, unique non-playable character and the true main antagonist in Warriors All-Stars. The supernatural being who shares her form calls itself Yomi (夜見).

Role in Game
She is Tamaki's and Shiki's mother and Setsuna's aunt. She is the only priestess blessed by the divine spring. When the spring dries up and her world begins to wither, Sayo informs her relatives that it is necessary to restore it and only Tamaki has the power to do it. Her words cause Shiki and Setsuna to distance themselves from the Holy Castle.

At the start of the game, she helps Tamaki summon the otherworldly heroes and introduce them to their world.

Development
Furusawa remarked that the original characters in Warriors All-Stars were originally designed to be human beings, but the team felt that their visuals "lost entirely" to characters from other IPs. They then tried to make the original characters appear to be "almighty", but this was declined for going too overboard just for the sake distinguishing them. Their current beastly appearances were originally suggested by one of the game's designers. It was accepted since anthropomorphism wasn't present in the other Warriors IPs that they had picked.

Personality
Calm and elegant, she is a perceptive woman who is loved by her people.

In reality, she is very manipulative.