Yin

Yin is the personification of the symbolic principle which bears her name. Just as in the philosophy, she cannot exist without her opposite, Yang.

In El Encuentro de Dos Fuerzas, the Turtles meet Yang and tell him about an evil earth spirit which they tracked to Mount Shasta. Yang fears bad things, and sees a battered Yin, confirming that the being vexing all of them is Kurko. Yang's ally Kutuk takes Yin to recover in sanctuary and after the defeat of Kurko, she recovered.