Deathwatch- Watchfortress Mnemom: Fidelis Ultra Mortem- Brotherhood Beyond Death
The mysterious, sometimes enigmatic, usually tactical, Black Shield.
The few times Yusuf has been out of armor he wears a dark coarse robe and cowl that hides his face. He speaks High Gothic with an unfamiliar accent. Rarely, in moments of extreme stress, he curses in a strange language.
His bolter is also of unfamiliar make — it has a shorter range, but on full auto fires many many bullets. His preferred deployment is an ammo backpack, a telescopic sight, and secondary ranged weapon for close combat. He hates aliens enough that he may not be able to resist attacking them in melee — though he is not very skilled.
Yusuf’s visual and audible acuity, especially with helmet enhancement, is off the charts. He often reacts to danger or clues in his environment subconsciously.
He refused the leader position on the last mission.
The observant may have noticed, on early missions, he hesitated before entering combat or enemy territory. This has happened less and less, and over the last (year long) mission, was replaced by the typical Space Marine eagerness to engage the enemy.
Also of note is his obsession and desperation to obtain the files found in the warp tainted armor found in the Tyrannid ship. He literally begged Brother Camino to translate them for him.