Sly Marbo, part of the Catachan II Regiment, is esteemed as the top camouflage expert and sniper in his regiment. Known as a "one man army", Marbo often operates alone, offering sniper support to his regiment's squads.

I’ve made this a flexible late-M41 profile, allowing scenarios around the Catachan II, Armageddon, the Thirteenth Black Crusade or independent classified deployments. His origins are deliberately uncertain in canon; the Ryza, Galabad, Pardus, Sask’s World, Nordassa and Dulma’lin accounts are preserved as recorded or rumoured exploits rather than perfectly verified history.