Kreed

Perhaps the most highly-skilled of the Quattros, Kreed was one of the finest hand-to-hand combatants known (in the Nexus universe), as well as a master of seemingly all weapons.  He was famous for his collection of weapons – so much so that only after his death was his vault opened, revealing an unmatched arsenal.
 
Trained by the Gucci’s, the galaxy’s highest order of assassins, Kreed was among the greatest killers alive.  He met his match in Nexus, and immediately developed a bond with him as a man of power, honor and wisdom.  He pledged his duty to Nexus and aided him on several missions/endeavors, always proving too much for any adversary to handle.  Although without a sense of humor, he managed to become the ‘strong, silent’ member of Nexus’ group, even protecting Nexus when the Merk took back Nexus’ powers.
 
Ultimately, he and another Gucci Quattro went too far on a mission and were responsible for a great number of fatalities on Mars.  Mars sentenced Kreed to execution, but Kreed chose to end his own life, dying in the arms of his friend Nexus.