Disclaimer: Avatar the Last Airbender copyright Dante Dimartino, Brian Konietzko and Nickelodeon Studios.
When she'd impersonated The Painted Lady, it'd been to act as a benefactor to a starving town, a healer to the sick and a guardian to the weak. The benevolent nature of The Painted Lady wouldn't break the hold Koh had over the Earth King.
She needed something fiercer, more haunting.
Katara had often been told blue was her color, so she thought it ironic that was the mask Zuko had left her. The smiling oni mask of the Blue Spirit seemed to agree as she tied it into place.
Koh was right; having two faces did come in handy.
