Building a Heroic Army

Loot Suramar treasures to increase your ancient mana cap by 500, and run the normal mode version of the scenario a couple of times to unlock upgrades for your withered. A score of 400 or higher in normal mode ensures the reward chest provides enough ancient mana to rerun the scenario.

Bring at least 15 withered into the heroic run — more is better. There is no time limit in this scenario, so wait for your cooldowns between pulls, as the added Legion monsters and hard mode affixes will kill your withered if you rush.

Use AoE abilities to tag mobs and maintain aggro at all times, as enemies will one-shot your withered if they pull threat. If a mob is empowered with an ability that deals damage when it dies, CC it and kill it within 8 seconds to disable that death effect.

Use your artifact weapon's summon demon ability for every Volatile Wraith encounter, then detonate your demon when the Volatile Wraith reaches around 30% health to instantly kill it. Pop all major cooldowns on the Arcane Shades, as these are the major bosses of the run and must be burst down quickly before they wipe your army.

Skip all side rooms that require previously empowered withered to enter, and stop before reaching Leystalker Dro, as he will likely kill your withered. Once your score reaches 200 or higher, exit properly through the scenario's built-in exit — do NOT right-click your portrait to leave, as that will teleport you out of the instance without granting the achievement or rewards.