A former sergeant in the Hlondeth militia, Basilus is a mercenary with connections.

Basilus seems to know everyone. And everyone seems to know him.
 
A former sergeant in the city militia, Basilus hires himself out as something of a sergeant for other peoples' projects. He isn't pushy and doesn't give orders; he asked Svent and Shay during their first foray into the Hall of Mercy how they wanted to proceed and only offered solutions when pressed.
 
He offered to work with the two of them again, and even went so far as to suggest he may come find them for his own future jobs.