Dodge

Dodge (Under the alias of Skye) is a Sheikah warrior trained by Impa in ranged combat and ancient Sheikah arts. She opposed Riju in a fierce battle and went with MrSmartguy to see whats going on with the Yiga Clan. Later, it is revealed that Skye is a demon called Dodge

Possessing Skye
Some point after Skye was born, Dodge possessed her body, taking control. The only incident where Riju was suspicious of Dodge was when she said she was a demon from another world, which Riju considered pretend at the time.

The murder of Riju's mother
Dodge pretended to be devastated by her mother's assasaination so she could join the Yiga. Dodge presumably did this to communicate with Fillamo or Eric, however no evidence supports this.

Riju's savage attack on Hyrule
Dodge joined MrSmartguy in an attempt to remove Riju from the picture. However, she knew that MrSmartguy might eventually blow her cover, so she made it impossible to detect her status as an Echo.