Honsou

Honsou is a Warsmith of the Iron Warriors, a half-breed of mixed gene-seed the Legion never stopped sneering at and never quite managed to kill. He took Hydra Cordatus, inherited a Grand Company, and then made a private war of the rest of Perturabo's sons.

He lost Khalan-Ghol, won the Skull Harvest, and brought the Bloodborn into Ultramar to settle a grudge with Uriel Ventris. Medrengard is the fortress. Calth was the insult. Ventris is the unfinished business.

The Iron Warriors respect results. Honsou keeps supplying them, which is why the sneers have not been fatal. Perturabo's lesson was siege. Honsou's is persistence.