The Fimbetamur: Five Random Things

Welcome to the whatnot about the world I made up. Today I’m gonna ramble about the Fimbetamur, which is important in both of my things (the things that I have so far, anyway).

The Fimbetamur is the High King (or Queen!) at Shirith’s gift. He or she keeps the volcano Fimberevell in check so it doesn’t erupt, and in return receives all the power of fire (plus magma/lava, earthquakes, and other things associated with volcanic eruption).

The Fimbetamur is Big Magic, which means it’s written in stone — all over the Palace at Shirith. The outer walls, the servants’ tunnel, and more places throughout the building are scribed with symbols and sigils to help the Rev Lieseassar in the exercise of the Fimbetamur.
The heart of the Fimbetamur is a tiny chamber deep beneath the Palace, lit only by tiny, fiery runes that cover it entirely.
High King Beagar, his father Bearan VI, and his father Beamar II are the only High Rulers never to visit the heart.
Tradition has the founder of the High Kingdom at Shirith, and the first wielder of the Fimbetamur, as Bearach I. Very little is actually known of him, as any record has long since fallen to dust.
The Mountain Fimberevell is Herself sentient.