Originally Posted by
Ardenaso
I made this profile just to be able to comment here. Here's my take: (it's a bit cringey though)
After Sylvanas' defeat at Orgrimmar, one of the Horde's loyal Dark Rangers (or probably one of the pre-Cata Forsaken) ha a request to you: to seek out the former Blackthorn allies of Sylvanas and recruit them to the Horde before Sylvanas takes them for herself. Lor'themar is having second thoughts because he recalls many of his comrades being assassinated and slaughtered in Tarren Mill in the Second War; but Eitrigg tells him that they had no choice back then as they were virtually held hostage by the demon-infused Orgrimm and they didn't want to risk their entire kingdom getting slaughtered in exchange; he also recalls that abandoning the Alteraci when they needed the Horde in return of assisting them was also one of his greatest regrets, as Orgrimm himself saw Alteraci Footmen, Knights, Mages, Priests, and even resisting civilians getting cut down by the Stromgarde army. Thalyssra also reminded that the Horde is supposed to be mending its wounds like how the Nightborne did after the sacking of Elisande
In the Dark Lady chapter in WC3X, the Mercenary Camps were colored orange, which greatly implies that the bandits were from Alterac. The Warcraft RPG also says that the Alteraci managed to loot Lordaeron while it was being Scourged; although it's now non-canon, there are no other sources that disprove this otherwise.
Beyond here's is purely made from my headcanon
After the Burning Legion and the Scourge's defeat at Lordaeron, the Blackthorn bandits witnessed Sylvanas and the Forsaken murder Garithos and his men and so they decided not to cross her. Lord Blackthorn instead approached her and gave her thanks for saving his men who were just about to get cornered by the Legion's undead and so they departed from Lordaeron. Like the Ravenholdt, they are at odds against the Syndicate, and so they decided to just ditch Alterac as well. They raided Southshore and stole the last ships there and sailed somewhere else instead. (This was also a great opportunity for the Syndicate to ransack Southshore and assassinate the Magistrate there)
Presently they are a discreet pirate group consisting of Ogres, Humans, and Forsaken roaming around Zul'dare (their main base of operations after it was abandoned by the Horde and the Alliance) and just around Booty Bay. The character travels to Zul'dare to attempt to negotiate with Lord Blackthorn but the people there say he's in his flagship near Booty Bay.
Then the character goes to Booty Bay and spots the flagship on the sea fighting some Kul Tiran vessels. The character would conveniently spot a boat and use it to reach the flagship and aid the Ogre and Forsaken pirates fighting the Alliance. After the battle is over, Lord Blackthorn (now a Forsaken) and a suddenly-and-conveniently-inserted-young-Perenolde appears to the character and so the character states his intentions. Lord Blackthorn expresses his dismay that Sylvanas would go the same path as Arthas did and she is no longer the savior that the Blackthorn bandits looked up to. While the young Perenolde expresses of joining the Horde to help deal with the increasing Alliance attacks, Lord Blackthorn says that their numbers are too few to be able to contribute anything for the Horde, and so Perenolde also thought of pooling all the other human bandits that are against the Alliance, as well as taking in some unsatisfied Stormwind citizens.
The character then goes around Azeroth to rally willing allies - Vanessa VanCleef and the Defias remnants - the Fogsail Pirates - the disgruntled Westfall and Redridge farmers and homeless having enough of hunger - Kira Iresoul for being a former Alteraci citizen and for infiltrating the Argus Wake - Jorach Ravenholdt for being a former Alteraci noble - some Syndicate Turncoats - and promise them safety and insurance in the Horde
But before they officially join, the character goes to Alterac Valley and defeat the last of the Syndicate - Darbel Montrose, Singed, and a small paltry force of Syndicates - as well as the last few Stormpikes who remained. Some Alteraci masons appear and begin rebuilding the city; and then the character travels to the Frostwolf Enclave to assure Drek'thar of the forged alliance of the Alteraci to the Horde.
Later on, Lord Blackthorn and Perenolde appear to the Grommash Hold to introduce himself as the leader of the Alteraci Humans; Baine, Rok'han, Thrall, Eitrigg, Geya'rah, Voss, Thalyssra, Velonara, and Mayla welcome him but Lor'themar remains skeptic. Perenolde then assured that he will help bridge gaps and ease the pain between the Blood Elves and the Alteraci, just as how the Orcs and the Blood Elves did.
Racial Leader: Lord Blackthorn (actual leader, forsaken), Prince [insert-name] Perenolde (figurehead)
Capital City: Alterac City
Other settlements: Tarren Mill, Durnholde, Strahnbrad, Frostwolf Valley, some random farmsteads in Suramar and Mulgore, Zul'dare, Plunder Isle
Notable NPCs: Jorad Ravenholdt, Kira Iresoul, Vanessa VanCleef, Menag (forsaken), Benedict (forsaken), Vallea Twinblades (forsaken), Kris Legace, Master Ryson
Classes: Warrior, Hunter, Mage, Priest, Paladin (some Alteraci have integrated into the Blood Knights), Shaman (some Alteraci have integrated with the Frostwolf Shamans), Warlock, Monk
Also, despite the Blackthorn consisting of Humans, Forsaken, Ogres, and a few Death Knights who rejoined them, the playable Alteraci is only the Alteraci Human
Bonus: the death knight Isiden Perenolde expressed his dismay of the Alteraci joining the Horde and so he sought out and rallied some few Alteraci who would join the Alliance and so he represents the Alliance loyalist Alteraci (this is more of a callback to the Silver Covenant), and he aids Raleigh and the Silver Hand in clearing Southshore and using it as a staging ground against Alterac.