It makes you think the relic is affected and the summoning of the 3 Shades depends on this condition. But you can destroy the relic anyway and the Shades will spawn. It will trigger no matter what. Y Also if it were a relic condition, the Shades would spawn right after the relic is destroyed, since "the effect has ended before it expired". So either you want to destroy it toprevent the spawn, or to accelerate it, both are incorrect ways of looking at it's effect and there's no way to tell what it does by the spell description.
