Lotara Sarrin

Lotara Sarrin was shipmaster of the Conqueror, the World Eaters' Gloriana, a mortal the Legion learned not to ignore. She took the flagship young, wore the Bloody Hand, and kept the guns firing while Angron murdered his way through the decks.

By the Siege she was holding a Khorne-touched ship together with a skeleton crew and a conspiracy to teleport the primarch off her bridge. The woman fused with the hull. A wraith of her still walks the corridors ten thousand years later as The Mistress, arguing with Kossolax and pledging the ship when Angron returns.

The Conqueror never got another captain who counted. It did not need one. It kept her.