Headed South

Enter Lost City of the Tol'vir on Heroic Difficulty and make your way to Siamat. Once engaged, Siamat raises a shield that reduces his damage taken by 90%, so the fight revolves around managing his adds rather than burning him down directly.

Siamat spawns two types of adds: Servants of Siamat (melee) and Minions of Siamat (casters). Only Servants grant Lightning Charge stacks — you must be in melee range when a Servant dies to receive the buff. Minions should be interrupted and pulled to the edge of the room, as they cast Chain Lightning and leave damaging clouds on the ground when they die.

Do not rush to kill Servants early. Let all three Servants of Siamat spawn — this happens within a minute — while managing Minions by interrupting and repositioning them. You do not need to damage Siamat at all during this phase; focus on positioning the Minion clouds away from the area where your group will be fighting.

Once three Servants are present, kill the first Servant while standing in melee range to gain your first stack of Lightning Charge. Kill a second Servant to reach 2 stacks, giving you over 20 seconds on the debuff with the ability to already begin damaging Siamat. Before the buff expires, kill the third and final Servant to reach 3 stacks.

With 3 stacks of Lightning Charge active, burn Siamat down before the buff expires. Avoid walking through the Minion clouds on the ground, as taking damage while holding 3 stacks of the debuff significantly increases the damage you receive from Chain Lightning. The achievement is awarded upon Siamat's death while all 3 stacks are still active.