The general name for the boon granted to the royal families when the Alchemist wrought the bodies of the earliest kings and queens anew, to make them not just magically but also physically more powerful than the general populace. Elementals to this day possess the boon also, but in a form much-diluted from its original incarnation.
Normal muscles function in strands, capable of only contracting linearly along the length of a given muscle fibre. In the case of the first royals, each of these linear muscle fibres was replaced with a coiled fibre contained within a sheath. These coiled muscle fibres were able to both contract and extend, and their being housed within a containing membrane allowed their linear extension/contraction to be greatly amplified. Specifically, the myofibrils within muscle fibres are oriented in a helical arrangement along the length of the muscle fibre.
In the retina, the vast majority of people have three kinds of colour-sensitive cone cells. Genetic mutations mean that some women have four such cones, called tetrachromacy, but lack the visual processing faculties to make use of these additional optic cells. The earliest kings and queens were functional tetrachromats, able to both perceive colour differentiation more finely, while also having vision that passed outside of the standard visible spectrum and into infrared and ultraviolet light.
Regular bones are composed of a softer, porous marrow wrapped in a dense and tough outer layer. In royal descendants the long bones of the body are instead composed of small helical strands of bone close together, with these individual strands being composed much like normal bones. The result is bones that are much harder to snap or fracture, but that also spring back to their original shape when exposed to torsion that would otherwise permanently bend the bones into a new shape.