Courage

just some PDF trooper taking some SLAUGHT to ready himself for combat

SLAUGHT is a powerful and volatile brewed drug commonly found in hiveworlds it's name is an acronym which stands for Sacred Libation And Unguent which Gives Heart to the Terrified it's basically a berserk drug it's usually illegal due to it's harmful long term side effects but it is still utilized by most combatants of the underhive from mutants and heretics to crusaders

so obviously he's taking some non standard issue stuff