Mafia 40. In the Name of the Emperor

Okay, let's figure this out. Visrit is a stormtrooper who was healed by an apothecary. Drakkosha, as can be seen from the description, is a bibliarius – the staff and sword clearly indicate this. She tries to kill him, but what happens? Who is her killer? The commander of the fifth company? One could assume that there was a redirection here, but two murders by the same mafia?...

I think that Koshu was killed by K.T.O., who was guarding Visrit. After all, if the Nereus-techmarine was redirected to Mortulus, then he could very well have been his own fifth captain.
The option of Koshu being killed by heretics is possible if the fifth captain was redirected by a psyker, but: I thought about the role of Nebo – it seems that he was a psyker after all. Psychological training and a pistol, and shooting is just a record.
I agree to execute Mortulus, but I will still think about it and figure out what is happening, and make a list of roles.