Does anyone know the function of the god Hua Guang? I know he is diferent from Er Lang Shen. Isn't Er Lang Shen similar to the position of Wei Tuo? Any information would be greatly appreciated.
Amituofo! 'liandeng'

Hua Guang, a spirit of Fire.

After Hua Guang being captured and take refuge under Taoism, he was bestowed with a title of Marshal that assist Jade Emperor in the Heavenly Imperial Court.

In Folks culture, he's respected as one of the Chinese Opera Protector.

Hua Guang and Er Lang Shen are of different Deities, do not mix them up.

Wei Tuo is consider as a Dharma Protector whereas Er Lang Shen is given the authorities to do slaying of Demons, etc, so their tasks quite different.