The passions that drive Cail seem to be those of remorse and duty - making Cail sometimes uncomfortable to be around even if you aren't a Renegade, Heretic or some other enemy of the Hierarchy. Although he never speaks of his mortal life, he has been observed to be oddly deferential to Christian souls - going so far as to turn a discretely blind eye on occasion. The Shroudkiller has recently tentatively identified Cail as an ex-Cross member, but to date there has been no proof offered or found to support this theory.