Samus

Samus is a daemon of the Ruinstorm that speaks in a comrade’s voice and occupies a succession of borrowed bodies. It is not a Space Marine, although the voice claims to be that of the man beside the listener. It first took the form of a Luna Wolf in the Whisperheads, then that of a Word Bearer on Calth, and finally the Phalanx itself, after Mersadie Oliton’s warp-eye opened a door in Dorn’s house. Its principal weapon is a chant; the bodies it uses are temporary.

Ventanus stabbed the daemon with an athame. Dorn killed it, and it rose again in a new corpse. Oliton closed the gate at the cost of her own life. Loken later cut apart another of its bodies aboard the Vengeful Spirit, while a person on Terra read its name aloud as a ward.

Samus does not remain dead, and each destruction of a body has ended only that body. The Warp claims that the daemon was born from Loken’s murder, an account that conflicts with the daemon’s earlier appearances. Its footsteps were heard first during the Great Crusade and last during the Siege, and the voice continues to seek a new host.