Thera

Thera is the Titaness of fire, magma/lava, and power. She is the daughter of Gaea and Ouranos. She was imprisoned in a volcano at the end of the First Titan War, but managed to escape recapture at the end of the Second Titan War.

History
At the end of the First Titan War, Thera was imprisoned after a volcanoe on an island that came to be named after her.