Rotation This class doesn't utilise a repeatable rotation or priority system. Instead, you have to be aware of your skills and adapt to the situation. This is because Exalted Harbinger (and its duplicates) thrives on being at very low HP as your main damaging ability, 2 (Soul Rend), deals damage based on your current HP - the lower it is, the more damage it deals. Therefore, you'll want to use 2 on cooldown while 5 (Blood Price) is active. 5 is used because it increases your damage and crit chance at the cost of HP.Before the fight, you should use 5 and see how hard it hits you (weapons like Burning Blade that boost damage to All will also increase the self-damage of 5). Don't use 5 again without being above that amount by around 300 (or however much you're comfortable with) otherwise you may kill yourself. Another important thing to remember is that 5's cooldown is shorter than its aura duration. Since it increases your damage, if you use it again before it fades, you'll deal a lot of damage to yourself. Avoid this by waiting for it to fade unless you're doing it strategically. Try enabling Class Actives/Auras UI in Advanced Options so you can see your aura durations. Heal with 3 (Soul Leech) when you need to get enough HP to use 5. Use 4 (Soul Snare) on cooldown to reduce the boss' DPS
Purchase for 2k Legion Tokens at /darkbirthday during Dage's Birthday event in March. If it's not March, you can buy Exalted Soul Cleaver, which is the same class and is permanently available at /underworld.