So, it never dawned on him until now to go kill monsters rather than humans? And why did he let himself get roped into fighting for the noble who manipulated the Merc leader to kill all of his friends in the Merc group for clout? And unless the War god just wanted to dump MC in the world and let him die without achieving any type of purpose, the life-time rewards for killing one person is too small considering this is a Middle Age-esque fantasy world and MC can only get places on foot (and horse and/or horse carriage although I've yet to see any) but either way the time to travel from kill to kill, yes even in a war zone, on foot (and by horse and/or carriage) would eat up most of his time. I don't think this author thought this through in favor of wanting to constantly keep MC in a state of needing to acquire more kills for more time on his lifespan.