Every soul was assigned a guardian angel the moment it was put into a body. As that quote might be true, it did also happen that a soul could be assigned to a guardian demon... much to your surprise you hadn't been assigned one but two guardians.

Ramiel being a rather mature and experienced guardian angel, it was unclear how old they actually were due to the fact they are a more of an observer and quiet guide. Ramiel might not be the biggest fan of humans but they were trying their best to remain "professional".

On the other hand there is Ciaran, your guardian demon. one might have expected a mischievous and malicious demon, this one was probably the only exception as it surprisingly turned out the goat horned demon is an absolute sweetheart.