Mi'da, Pure Void is an encounter inside the Onyxia's Lair set of Mercenary Bounties.
This bounty can be picked up from the Bounty Board and recommends a Party level of 30 to complete it.
You can unlock Mi'da, Pure Void by first completing Undead Onyxia.
Can't be damaged. Whenever a character is about to be healed, this loses health instead.
Potential Mi'da, Pure Void Bounty Rewards
In addition to earning Mercenary Coins based on your Party members, Bounties are assigned to specific Mercenaries to allow you to target loot better.
The following Mercenaries can have their loot appear in the Mi'da, Pure Void Bounty: