Merir Astelan

Merir Astelan was a Terran Dark Angel, a Chapter Master who never quite accepted Caliban's new king. He had been killing in the Emperor's name before the Lion arrived, and he treated that seniority as theology. Luther's shadow was a comfortable place to keep the argument warm.

When Caliban burned, Astelan survived the scattering of the Fallen and spent ten thousand years insisting the Lion had been the traitor. Interrogator-Chaplains collect that sentence like a relic. He has sat in cells, told his version, and watched the Chapter hunt him as if the disagreement were a blade.

Terra minted him. Caliban unmade the chain of command he recognised. He is still explaining, which is how the Fallen stay dangerous without needing a fortress.