Alchemical Romance

1. Engage boss
2. Kill adds immediately as soon as they spawn.
3. Walk over any of the light circles that spawn on the ground to gain the special ability.
3. When you have at least 3 corpses in a pile together, use the special ability on the pile of corpses.
4. Kill boss.

That's it.

To get this achievement you can't use any Alchemical Fire vials that Yorrick throws down during the fight until you have at least 3 Deathtouched Slavers. You must kill them as soon as they get summoned or revived and don't start casting Death Lens. When you have 3 or more up at the same time it could get dangerous if all start casting it and multiple people get stunned. Have everyone stay close to the boss so when they use Dark Leap they will still be in aoe/cleave range and their corpses can get hit by the Alchemical Fire.

During the [npc=144324] encounter, the boss will periodically toss out [spell=266198] which you will need to use to burn the corpses of Deathtouched Slavers, so they can't respawn. Once the boss casts [spell=266266] and summons the third add you will have to nuke the adds, and then quickly use [spell=266198] to burn their corpses.

If you need help with the other achievements, check this TLDR guide for all achievements: [guide=6418]