"Is it not fitting for He who steals the stars to utilize their power in every attack? But still, they are nothing to me. Merely a structure for one's own personal abilities to shine atop."
~Stjarnstill~ The one who created the style.
Created by Stjarnstill from a young age, the young God created Stjarn Hnefa, meaning Astral Fist, as a fighting style independent of others, nigh on impossible to read unless one knows it themselves. It was also crafted to work around the Dust Complex, several tattoos of dust all around the body, with exact placements of tattoos up to the user. For example, exclusively red dust could be used for a more Fiery Stjarn Hnefa.
Using elemental attacks to bolster physical attacks, the enhancement is only a small part of the style, more of it dedicated to the combat itself. Stjarn Hnefa uses the Dust complex to the fullest while delivering fast punches, kicks, and throws. It is a nimble style, relying on slides, flips, and jumps more than other grounded martial arts. Any kick attacks are meant to leave the hands unused and free to act, often preparing for follow up attacks.
Due to the low damage of its weaker attacks, many are made to harass, be it slides underneath the person to trip them up, or repeated strikes to the back of the head after jumping over them. While the creator often does use it to great effect against other humans, the style works quite well on many kinds of grimm as well.
The fighting style derives some of its attacks and basis from Shadowlooism, the fighting style practiced by M. Bison (Vega jpn) in the Street Fighter series.
Should probably ask me if you want to give your character this. Stjarnstill isn't much of a teacher, but he thinks he's a god, so he can be buttered up.