All demonic magic (aka magic from Niflheim) has it’s basis in shadow magic. no matter how the demon manages to use this ‘negative energy’, the basis is shadows, so even healing, ice or fire demon magic has a shadow core.

Shadows from the Shadow Realm however, are something like an embodiment of this magic, and are thus pure magic… a magic that hungers for ‘positives’. Mainly, they hunger for souls, ideally of Valhallans since they are the ‘sweetest’, but any Midgardian or even a Demon of pure heart will do.

Only those Demons with Surtur blood can command these embodiments of magic, the rest can only manipulate the essence of Shadow magic. This is why Surturs are so much more powerful than regular demons.

Certain high-ranking, powerful Surturs… those that belong to the royal bloodline, can not only bend the shadows to their will, but can take on Shadow Servants, commanding over certain shadows who become something akin to slaves to that Demon. This contract is dangerous, and very powerful. With a Sadow Contract, the Demon has access to even more powerful magic.

The more shadows a High Surtur can command, the more powerful they are. Only two have command over all Shadows… the Queen or King of Niflheim, and the Queen or King of Muspelheim. Ceranda proved just how powerful she was by creating a ‘tangible’ shadow, Vitlo, whom she commands at will while being a servant to her, and a ‘spokesperson’ of the Shadows of the Layer.