Potency is a Divine in the Divine Fleet. Its people are on The Ever-Forward.
The Divine's specialty was terraforming planets and moons; at the height of their capability they were even able to transmute one type of resource into another, quickly changing planets and substances to their needs.
Physically, its ship has a couple spheres that rotate within it. Potency lived in one opaque sphere (the other spheres being translucent) which could forge a path ahead of the fleet and facilitate their needs at an accelerated pace.
While trying to transmute one thing to another, Potency made a never-before-seen error, altering a planet's mass, throwing it out of orbit and into a star. It was going to collapse and kill everyone but instead Potency stayed behind to allow the fleet to get to safety, sacrificing themself in the process.