Futao & Mote were one individual, who was really REALLY bad at parenting.

She always let her impulsive thoughts take over her, and neighbours in her village started to shun her behind her back.

Therefore, she made a deal with the devil, hoping to become normal again.
The devil told her that if she eats the spirit, she would become normal again.

"I've became far worse."

So yeah thats basically how Futaomote was formed (Futao is the calm one, Mote is the one behind her back with an impossibly wide ass smile)