Players who were around during Mists of Pandaria might recall a dungeon mode called Scenarios, which involved teams of three players instead of the traditional five. Island Expeditions bring a similar feel, with groups being tasked with plundering treasure off various islands. Your team faces off against other players or AI-controlled characters from the opposing faction and whoever can collect the most treasure, or "Azerite," wins.
Blood Elves and Dwarves gain access to Heritage armor as part of 8.1, as well, without a prolonged quest line, though they’ll need to be exalted through Silvermoon and Ironforge, respectively, in order to receive it. A Warfront called The Battle for Darkshore focuses on the struggle between Night Elves and the Forsaken. During the Warfront, you’ll be able to transform your character with temporary abilities, and when your faction controls either the Darkshore or Arathi Highlands, you’ll gain access to world quests.
This top-end difficulty was missing entirely from Legion’s first raid, Emerald Nightmare, which was cleared by top guilds in around 11 hours. Meanwhile the first guild to clear Uldir’s hardest difficulty, Mythic, spent somewhere around 70 hours attempting to kill the raid’s eight bosses. Even after all that time, the guild, Method, still had members say they loved the raid, and that it was one of their favorite in recent memory.
Mag'har orc - "For untold generations, the orc clans of Draenor battled one another in endless war. But when Gul'dan offered them the blood of his demonic masters, the disparate tribes of Mag'har—the orcish word for "uncorrupted"—refused the dark bargain and banded together to drive out the Burning Legion. United under the leadership of Grommash Hellscream, the Mag'har pledged to one day repay Azeroth's heroes for aiding their cause. As war against the Alliance intensifies, the Horde must call upon the might of the Mag'har to seize victory."
While it’s clear that Blizzard is eager not to spoil the future of Battle for Azeroth, it seems pretty unlikely that players who want to be pure evil will ever get their day to shine in World of Warcraft. Despite the decision being added into the game, the good guys will likely win and the threats to Azeroth will continue to roll on by, getting knocked out by players one at a time.
The idea of the expansion came up after the heroes of Azeroth dealt with so much external threats like the Burning Legion. In their own words, "so when we talk about what's the biggest threat in this world, is it the titan or is it the dwarf paladin that put a hammer in that titan's head"? As such, the enemy (at least during the early parts of the scenario) will be the opposite faction, a "vast army of world-destroying forces".
As the battle for Darkshore begins, both the Alliance and Horde are blindsided by a new development: High Overlord Saurfang, who had been defeated and captured in the Battle of Lordearon, has suddenly escaped Alliance captivity and is on the run. Sylvanas sends Horde Champions to track Saurfang down, ostensibly to extract him. However, it quickly becomes apparent that the search party is in fact an assassination squad, as Sylvanas suspects Saurfang of colluding with the Alliance in an attempt to dethrone her. While some Horde champions choose to side with Saurfang and help him escape the assassins, other champions remain loyal to Sylvanas and report Saurfang's and the dissenting champions' treachery to her.
I do not recommend going for TBC, although I remember Hellfire peninsula to be decent, everything else is rather slow. Instead go for WotLK, Borean Thundra gets you levelled very fast, and then you can head straight for Icecrown at 67, which is also insanely fast, although admittedly has a few elite quests. You can go to Sholazar Basin alternatively. 2 zones should get you 60-80 no problem.