A celestial demon is someone who defies fate, who would do anything to gain power. Killing, Massacring, Sacrifices, that's why I can't see him as someone who pretends to be weak.
You may not like it, but I believe he is a celestial demon, who is supposed to be born to challenge the sky. I don't think someone like that hides their power.
I would say that it is better to call it a demonic tree, but otherwise, it is very good.
If you know Fang Yuan from Reverend Insanity, you can get ideas from him. He is the perfect representation of what a celestial demon is willing to do to accomplish his goals.
Naruto: Heavenly Demon Template
Anime & Comics · Lord_Aesir