Darkness (character)

The Darkness is a mysterious character introduced in Kingdom Hearts Union χ.

Kingdom Hearts III Re Mind
When Sora begins his journey to restore Kairi's heart using the power of waking he first enters Ventus's heart, when attempting to wake Ventus he is stopped by an entity referring to itself as "Darkness". Sora questions if "darkness" is Vanitas, but does not get a reply as the entity forms itself into Dark Inferno χ and battles Sora.

Kingdom Hearts Union χ
The model used for the Darkness is also used for Strelitzia's killer. It is unclear whether this means they are the same character, or whether the model was merely used as a placeholder; the series has previously used placeholder models, such as recycling Saïx's hooded model for Young Xehanort's appearance in Kingdom Hearts Birth by Sleep.