Chainbreaker

Once a different dragon by a different name, Chainbreaker was captured by a holy order of dragonslayers. They kept him bound both in chain and blesséd bindings, and harvested his blood and scales to create potent dragonkiller poison.

Though a dragon's major element is set from birth, they grow into their minor one - and it can change.

Chainbreaker endured; endured the humiliation and pain of his capture. Within himself, like an oyster nurturing a pearl, he hoarded his agony. Nurtured it, concentrated it, allowed it to suffuse and transform him. It cost so much, but his rage granted him fuel enough to break his bonds and escape.

The sect of dragonslayers - those who weren't killed in Chainbreakers escape - survives, but has fallen far from grace: more of a paranoid cult than their former glory. Each member knows themselves marked, hunted, cursed - for Chainbreaker will finish nursing his wounds and return for his vengence.

They scramble, hardly a unified force anymore, for any scrap of magic or power that will defeat him - but most of the time their desperation only harms themselves.

It is unknown where Chainbreaker is resting. He has no territory, no hoard, and is more a force of hatred than a dragon now.