The Affinities Cycle is an epic fantasy saga in a Farlandesque or Sandersonian vein… 5/5 stars, and bring on the sequels! As in Sanderson’s and Farland’s most famous books, magic here is schematic, tied to an ordering of the world, its cosmology and myth. Specifically, the Heart of the World is an ur-gem with twelve aspects that sometimes seem like principles and sometimes seem like deities: the four Material aspects of air, earth, fire, and water, the four Energy aspects of density, force, magnetism, and time, and the four Conscience aspects of will, emotion, perception, and spirit. Some races in this fantasy world have magical powers tied to specific aspects; the advantage and also the weakness of humanity is that it is tied to none of them specifically, but has people talented in all the aspects.
(Having said this, the very setup of the tale in its “Chapter 0” prolog suggests that the scheme only incompletely describes reality.)
Bloodletting opens with a pair of human siblings. Tetra is a Graviton, with a great natural gift for manipulating the density of objects. His twin sister Halli is a Geist, with a gift for manipulating spirit. They are both chosen to have their talents further groomed at the Academy, only before they can go, their home village is ravaged by the Orocs, an orcish / entish species of tribalistic earth manipulators. Halli is kidnapped, and Tetra is maimed.
So Tetra determines to rescue his sister. In the meantime, the military commander who intervened to save Tetra’s life in the massacre tries to understand why Tetra seems to be able to do unique things with his powers. And in the background, all the races move closer to a world-engulfing war over the missing Heart of the World.