BloodBound (2007)

Vic and Stan reliably carry out assignments and courier services, which may involve the use of forceful arguments. When they transport a seemingly empty suitcase to a bar full of strangely tattooed guys for their boss, they get into a fight and Stan is injured. Later, they both learn that their opponents may have been of demonic origin and were seeking world domination. Vic sides with their opponents, but discovers that Stan has already been infected by the demons.