[Demons can be simple servants but that's not all they are... tbf, it's the same for any other servant, of course.]
Well, messiness among other things. [You can't PA-ly insult her like that, Sebastian, bring your A game. Or go after her age. Time flicks her finger and a bit of the goop springs up from the floor to try and hit Sebastian's cheek. This is such an appropriate use of her divine abilities.]