Maw of the Void (Achievements) | Campaign - Artifact missions SC II: WoL Guide
Last update: 11 May 2016
Maw of the Void:
Clear the Landing Zone, Destroy the Xel'Naga Vault, Rescue the Protoss Prisoners.
I Have the Power:
It's a very time-consuming mission, but medals aren't given for free. The generators'' locations are no secret, so I may just wish you happy hunting.
Master of the Universe:
The description might not give a full view of this achievement. From what I've learned, you can't let the Field itself kill any of your units, if any gets killed by an enemy unit while in the field, it doesn't count.
The sole fact of establishing whether the units were killed by the Field or the enemy is quite problematic. The Field drains little health but does it systematically and fast, so you never will be completely sure if the last health points were taken by the field or an enemy attack. Overall it's best to avoid any fights inside the field, though if you lose some units that way, you may still have hope (or saves).
On hard, the enemy has a powerful fleet at his disposal (every units from the Stargate), though his ground units are also dangerous (Archons, Colossuses and High Templars, amongst else). In return, build a large army of Battlecruisers, buying all upgrades for them in the Armoury. Their high endurance and firepower make them ideal for fighting your way towards the Vault. Have some SCVs or Science Vessels nearby, outside the Field for sake of quick repairs.
Note that your resources are very limited, even more than on normal. Don't hesitate from quickly taking over the nearby Protoss base and collecting the numerous mineral and gas tanks. Additionally secure not only the middle, but also the southern part of the map with a line of Turrets (vertically), as the Protosses will probably want to surprise you with an attack from there. If you command a group of Battlecruisers and come across several enemies at once (for example, Carriers), it would be advised to queue the Yamato Cannon shots by holding down Shift.