is starbucks demonic

Don't think that Starbucks is evil, It's the mermaid in their logo is a stab from Greek fairy tale which means it represents irresistible lure, is glamorous and beautiful yet attracts one's youth. Just like what follows are their drinks. But then again if by 'grasp' you mean their prices, that's up for interpretation! Finding mythological symbols in brands is more or less like discovering the Easter Egg of a well planned animation.

"Oh yeah? As for being 'demonical' that's only graphic! The little demon on the store's shield is just a variation of Dick Brorda’s design and adds great charm to it. What the Siren Azalea represents is a man made from water-she is like so-called monsters in Greek Myths Sirens Were lovely creatures which put sailors into dreaming sounds. And It's possible that this one word–Greek for "Enchanter"–Buffet is reasonably satisfied as a metaphor for an espresso which will (as it happens) tempt your palate and your sense I should think! But it would not do Ever so much horror anime you say.

Demonic? Nah, Starbucks uses a siren in its logo, a reference to Greek mythology. Their coffee can be seductive like a siren's song!

No, Starbucks is not demonic. The only thing monstrous about it might be the addiction to some of their drinks. Their logo is simply a design featuring a siren from Greek mythology. Entertainment culture like anime often portrays mythological creatures too.