Lords of Creation: Ancients of the Void
Spirit Magic is to Reapers what Elemental Magic is to a Wizard. While Reapers are capable of physical combat, many prefer to engage targets through magics. Spirit Magic only affects the soul of a creature, and thus is useless against creatures without a soul, such as Revenants, though if a Revenant becomes possessed by a Wraith, Spirit Magic can be used to harm that Wraith. Spirit Magic has two components, a physical and a mental.
The Physical component is summoned weapons and constructs which harm spiritual creatures or restrain souls. Reapers prefer to summon chains and hooks, and any bladed weapon is likely attached to some sort of chain, allowing it to be pulled back and forth, and entangling foes.
The mental component involves runes of power that must be inscribed by hand. While more dangerous to use for the Reaper, these runes are also much more powerful, as they inscribe a geass upon the Spirit they are inscribed upon. These runes are limited only by the creativity of the Reaper, and can be used in concert to achieve desired effects.