Heart of the Swarm Campaign- Skygeirr: Hand of Darkness (Part 3)

Due West of this Hybrid is the containment cell where you can find the second brutalisk, so you should take the opportunity while you're down here on the South edge of the map to go after that.  It is protected by a couple of bunkers and a thor in addition to several valkyries- but by now that kind of force is negligible next to your assault.  Take careful note of enemy troop movements, as it's easy to miss an incoming attack around against your base around this time while you're busy fighting off in the far corner of the map.  Since your assault units will soon be passing by your base, you should also take this opportunity to prepare any additional Zerg you want to have join in on the attack group.

Shortly after the death of the third Hybrid to awaken in the base, the fourth will break containment, accompanied by a threat/taunt from Naruud.  This Hybrid is guarded by a small Terran outpost that will slow you down en route- so make sure you're on your way with a bit of time to spare.  Also, be aware that the Dominion will soon attack your base again, and this time there's likely to be a thor thrown into the bargain.  While the location you're destroying a Hybrid at is nearby, distracting your forces from that assault may leave you without enough time if you've been taking advantage of the slow attacks of the Hybrids to build up forces rather than staying on a constant offensive.  Also, once you've started attacking the Hybrid, it will follow your assault force back to base if you turn away mid-combat.

Once that Hybrid is dead, the next begins to awaken in a Terran base to the due East.  This base is fairly large and sprawling but thankfully not much better defended than the West edge base overall- smash through it and into the Hybrid there with all the power you can muster, which should be quite a lot by this point.  You'll find anti-air troops becoming even more vital here, as the Dominion fields several wraiths and banshees to try and stop you.  The gunships thankfully don't often use their common cloaking ability, but it can pay to have an overlord on hand just in case.  Also be wary of your units getting rerouted around buildings by enemies attacking from the far side- this can lead to issues when you're trying to change the overall focus of your attack.