My sister thought you would like this headcanon: Erron had a daughter before he left to outworld that died and he has a soft spot for Ferra and can't say no when she asks to wear his hat because she reminds him of his little girl.
“Ferra want wear shoot shoot hat!”
Erron looked down at the young girl who was tugging on his shirt and trying to reach out for his hat.
for a second Erron didn’t see the wild outworld girl, he saw a little girl with dirty blond hair and bright blue eyes wearing a sky blue dress that her mother just made for her.
“can I wear your hat papa?”
“Ferra, cease bothering Erron for something so childish”
Kotal Kahn’s voice brought Erron back and he saw the look of disappointment on Ferra’s face.
“its alright emperor” he said as he picks up Ferra and took off his hat and placed it on her head, making Ferra laugh in glee.
“Ferra bang bang now!”
No one could see it but Erron was smiling under his mask.