Cult of the Undying God

Publisher's blurb:

The inhabitants of Gullykin, a small halfling village, harbour a dark secret; for generations they have worshipped the Undying God, an elven deity summoned and killed by power-hungry sorcerers in age bygone. The lingering consciousness of the god however still haunt the ruin of the elven city of Firewine Bridge, on which Gullykin was built. The villagers each year sacrifice the Spring King to the god and it feeds on the life essence to regain power and a corporeal form. If the Undying God will succeed and return in flesh and bone on the Material Plane, woe betides the Sword Coast and all its inhabitants.