I rolled a couple of times on the "Why these orcs are evil" random tables I previously posted.
This is the tale of the Shadow-Hands orcs.
4000 years ago: a Dark Lord befriended and subjugated the people for his own dark goals.
But his half-orc daughter, Ulra Shadow-Fang defeated him and liberated the tribes.
Humans have their own version of this story and tell how the alliance of the five blades defeated the Dark Lord.
600 years ago: a long and disastrous civil war violently teared them apart. The Shadow-Fang bloodline desired to create a alliance with the Winter-Moon barbarians but human interference and propaganda caused the downfall of the heroic blood-line of Ulra.
400 year ago: scarcity of a key resource destroyed their new way of living. The surviving tribes became aurocs herders but a disease destroyed the great herds and the clans became mercenaries.
100 year ago: scarcity of a key resource destroyed their new way of living. The new Empire dispersed the great human-orc mercenaries warbands and the orcs military houses lost everything, most of them became bandits.
4 years ago: rise of a populist leader: a populist orc leader target the humans and blame everything on them to gain political momentum. His clan raise in power and is seen as a menace by the alliance of five blades.
3 month ago: break of treaty: the alliance of five blade broke the treaty that let orcs work in human cities.
3 days ago: border disputes and skirmishes. The declining Empire start moving troops in the orcs territories to reclaim one of their former states.
Why they are not always seen as evil?
Some tribe members are know to work for humans (or to hire humans) and are appreciated for their competence. But since the break of the treaty they can't work in human cities anymore, this anger a lot of people on both side.
Outcasts from their tribe live with humans and adopted human culture. These are mostly descendants of the fallen Shadow-Fang bloodline.
Why it is complicated to deal with them?
They have a special character class that do something that seem repulsive. The Dark Hands still remember some of the rites of the Dark Lord. When becoming one, their hand blacken, wither and shrivel and grant them special necromantic powers.
They ritualise a specific activity and it take a longer time to do it. This is a remaining ritual from their herding days. To become the owner of a horse or to ride a new one, one must make a old ritual of bounding that take 1d6 days. The ritual give a advantage to any check made with that horse. Riding a horse without doing this ritual ensue severe reaction penalties.