Also note that power leveling is sometimes used to refer to paying someone else to level your character to cap as fast as possible (i.e. they power level for you); a distinction used by Blizzard is to refer to the paid leveling as "power leveling service." This behavior is against Blizzard's Terms of Service. Power leveling yourself, which this article covers, is perfectly acceptable.
Arms: Sharpen Blade - When activated, your next Mortal Strike will deal 15% increased damage and reduce healing taken by 50% for 6 sec. Fury: Battle Trance - You go into a trance causing you to regenerate 3% of your health and generate 5 Rage every 3 sec for 18 sec after using Raging Blow twice in a row on a target. Using Raging Blow on a new target will cancel this effect. Protection: Thunderstruck - Thunder Clap roots all targets for 1 sec. You can find a list of all Essences available in Rise of Azshara here.
“Power leveling” is a term used to describe getting a character to max level in a short amount of time. Essentially, someone who is power leveling wants their character’s level maxed ASAP so that they can move on to “end game”—gameplay intended to challenge max level players. This is an appealing practice for seasoned World of Warcraft players due to the fact that characters are required to reach level 100 to participate in a number of the more intriguing game play options. In addition to helping a player achieve max level more quickly, power leveling differs from traditional leveling due to its focus on boosting experience points through the use of special items, promotions, and gear. Also, while traditional leveling tends to be quest-heavy, power leveling often relies on running instances rather than simply moving from quest hub to quest hub. There are several different ways to power level, and many of them can be used in combination with others for a truly speedy leveling experience.
Vol’Dun is the hardest and most tedious of the Horde Zones in Battle for Azeroth. It’s also probably the one that makes the most sense. Each sections of quests leads directly to the one you should do next. For all of these reasons it’s going to be best to get this one done early. Thanks to any legendary items you might have collected in Legion, you’ll be strongest in the leveling process before 115 and weaker after — because that’s when the legendary effects stop working.
Drustvar is far and away the hardest Alliance zone, which is exactly why you want to do it first. If you have legendary items, they’ll still be usable, and if you don’t, this zone will still be easier early on than it will be later. Drustvar is also extremely fast and will let you jump out ahead of your competition in other zones, which means fewer players around to take your quest objectives.