Valkyrie's ring is a small black ring. It has no distinctive symbols or markings on it.
The ring channels Valkyrie's Necromancy powers and allows her to "feel" the presence of the dead as the ring gets colder when death is around her. She later gains this skill as her own, and the ring is only used as her amplifier. It also enables Valkyrie to throw shadows at her will through the power of Necromancy - which Skulduggery isn't too pleased about but lets her carry on with her Necromancy and Elemental training. She can create shadow whips, barriers and tendrils through her ring.