Infestation | Challenges SC II: WoL Guide
Last update: 11 May 2016
I have to admit I passed this challenge on the first try. It's very easy and the pretty much the only real enemy here is the time.
You begin with Infestor, who will pretty much fill the meter themselves. The area is swarming with powerful machines like Siege Tanks or Colossuses - you just have to take control over them and make them kill for you. Curiously, while the units are under your control, they don't seem suspicious to the enemy, even while their friends are being ripped to pieces. Basically, you can roam the Terran base freely with the dazed units - no one will attack it.
Even though taking over control is the key to success here, note that the Infestors will lose control once you send the unit too far away. If you haven't played with the Zergs before, you'd better test the length of such a connection in free play. You can get rid of the useless units (with, for example, Roaches) using forced attack. It's important, as in order to get the Siege Tank, the Infestor will have to get hit once. If he'd release a unit, it could end badly for him.
Watch for isolated groups of enemies and attack them by approaching while underground. Ultralisks have such an ability as well and moving that way is made easier by the fact that there are no detectors is the enemy base (at least I didn't notice any). You should also not that buildings increase the counter as well.
You do get a sneak peak at the enemy's units layout before beginning the mission, but I've marked those most worthy of taking over on the above map. Those are: Siege Tanks (green colour), Colossuses (orange) and High Templars (blue). Try to reach the Command Center surrounded with many easy to destroy SCVs with their help.