Pact of Darkness

Pact of darkness creates a pact between a Necromancer and a shadow giant. By agreeing to give the shadow giant ten perfect spheres of obsidian (100 gp value minimum) as payment, the sorcerer is empowered to call upon the shadow giant for aid. The shadow giant will use its powers on the wizard's behalf for up to an hour before returning to the Black. Each use of the spell calls for another payment of spheres. If the shadow giant is unwilling to serve the wizard, it is entitled to a saving throw versus spells. Should it succeed in its saving throw, the spheres of obsidian shatter and the shadow giant refuses to appear.

Shadow giants cannot be summoned in areas of absolute blackness. The material components for the spell are the obsidian spheres and a drop of the caster's blood.