Maitreya,
Probably one of the cheat options (enable cheats in launcher, then use the action menu to access the various kinds of developer commands) will help. Try spawning a looter party nearby, and see if he chases. Or maybe spawn a bunch and then engage and see if you can help shoot his men to death. There might also be something in the faction menus to change their commands, but if not, maybe just use "kill lord" a few times until it gets brand.
Probably one of the cheat options (enable cheats in launcher, then use the action menu to access the various kinds of developer commands) will help. Try spawning a looter party nearby, and see if he chases. Or maybe spawn a bunch and then engage and see if you can help shoot his men to death. There might also be something in the faction menus to change their commands, but if not, maybe just use "kill lord" a few times until it gets brand.