Luca

A former gangster who serves as the "muscle" of the Outlaw King Van Maximo.  Luca is sent by Maximo whenever people are getting out of line. Originally a small time criminal who ran a violent
 gang, Luca eventually befriended the conman Quinn and the two would 
form a dangerous pair with Quinn as the brains and Luca as the brawn. As part of a long scheme, Quinn suggested that they both join SENTINEL. It was not long after entering the Order that they would use their new 
found power to shake down criminals and make off with their loot. 
Eventually their actions brought them to the attention of Van Maximo who
 decided they would be useful and recruited them. Luca would eventually be elevated to the rank of Sergeant which allowed him the ability to carry out Maximo's whims without any undue scrutiny. What he lacks in intellect he more than makes up for in instinct and is said by Bruno to be one of the most dangerous fighters he's ever faced. 
According to John he resembles a shaved gorilla with a heavily muscled frame and over long arms. His expression is normally a squint, but when annoyed he'll open and glare with his right eye. After he was sent to back up Siri on a job in the past where she'd been cornered, she fell madly in love with him. However, if he's aware of her infatuation he does not acknowledge it, instead occasionally only praising her impressive talent
 for killing.