I've recently listened through the Protomen discography with the liner notes for the first time and have been reading History of Middle-Earth, so here are some narrative parallels I've noticed, presented in three acts.

Act I: Light Beyond the Shadow

The repeated motif of the persistence of the Sun, Moon, and stars regardless of the strengths of evil on Earth is something emphasized in several places in Tolkien's legendarium. Most notably Sam seeing a star in the dark of Mordor:

Far above the Ephel Dúath in the West the night-sky was still dim and pale. There, peeping among the cloud-wrack above a dark tor high up in the mountai