Manfeathers

"What is this scent? It smells of.... MANFEATHERS!" -Commander

Manfeathers are a radioactive alkaloid found most commonly in Sanguinius, bless his golden red feathery heart. When Sanguinius died, the essence of the Manfeathers was mostly extracted from his corpse and stored in a big vase colliqually referred to as 'the Manfeather Vase' so that his body would not be desecrated by those with a fetish for his wings and undeniable manliness. The Blood Angels (not to be confused with their shitty offbrand cousins, the Blood Ravens) zealously guard this vase and are prone to flying into bouts of rage when questioned about the wherabouts of the Manfeather Vase, as it reminds them their primarch is dead.

'Manfeathers' also refers to an extremely manly scent, such as sweat and stress pheremones mixed with the blood of fallen enemies. If someone tells you that you smell of Manfeathers, it is a compliment, and a huge one at that.

TL:DR - Manfeathers are something you can smell in an ork-flesh-induced psychosis and, if you are lucky enough to be a Blood Angel, the contents of the creatively named Manfeather Vase.