[@tobiax]

Explaining the powers a little more in depth.

Dragon Features: Although the specific effects can be altered using Dust, the general idea that a pair of dragon wings and a tail form from him pushing all of his Aura outside of his body, and are primarily defensive. The horns on his head are purely cosmetic. They are stronger/more resistant to damage than his aura on its own, but is offset by the fact that if they are destroyed then he has no aura left at all to defend himself with. If used with Dust simultaneously, the constructs take on appropriate elemental effects, including its weaknesses. eg Fire Dust forms flaming wings and a fiery breath attack, but are weak to water. The breath attack relies entirely on Dust as a catalyst, meaning no dust, no breath attack.

Decay/Mutation: The Decay is fairly self explanatory, and is pretty much how Raijin explained it. The Mutation, however, happens when the hunter used Dust arrows instead of normal arrows. Instead of behaving normally, the effects of the Dust seep below the surface of its target and begin to damage it from within. For example a Fire Dust Arrow would cause a fire to spread along the surface of wherever it its, but a mutated Fire Dust Arrow would behave more like Thermite, burning downwards rather than outwards.