Heart of the Swarm Campaign- Kerrigan Abilities: Malignant Creep (Level 35)

Malignant Creep is primarily a defensive ability, though there are ways to turn it into an offensive boost if you’re not so worried about time constraints.  While Kerrigan has this ability, your units that are standing on/flying over creep gain a 30% increase to their attack speed and a +1 bonus to their regeneration rate.  While it can be hard to implement offensively, this is a rather strong, reliable buff to your units that can easily tip battles in your favor.

The most obvious use of this ability is for effectiveness in base defense.  Units that heal constantly and attack faster will last longer and survive harsher assaults with less losses.  Since all your buildings are stuck on creep anyways to begin with, this is very easily implemented to ensure that the defending forces around your bases are ready and able to take anything the computer can throw at you.  This becomes particularly noteworthy if you use a combined defending force of swarm hosts and either lurkers or impalers to defend your base from cliffpoint vantages- while the locusts that are produced by the swarm hosts aren’t always going to benefit, faster lurker/impaler attacks can mean a huge increase in damage to incoming enemy forces.

Using this ability offensively takes a lot more management and should really only be considered by master micromanagers.  Creep in Heart of the Swarm is easily spread through the use of queens and the creep clusters that they can produce- which are capable of producing additional creep clusters a short time after they have been placed.  Unfortunately, all creep clusters must be placed on creep themselves, so without a significant number of queens, spreading the creep to your combat theaters becomes prohibitively slow.  That said, if you can manage to actually spread the creep, this buff becomes an important improvement to your entire army- and it is that much more useful with ranged attackers, who don’t need the creep to be as close to enemy forces as a melee squad might.

Because of its reliance on creep and odd methodology, there are a few units and abilities that this combines especially well with.  Most notable is the Deep Burrow ability that can be evolved for swarm hosts, but it can also be used with the now-uprootable nature of sunken and spore colonies to create an army of what essentially amounts to a wandering defensive wall.  This isn’t the most efficient way to do combat, but it is reliable and stable if you can get it working, and the Malignant Creep buff makes it that much more durable of an offensive force.  That said, it’s really a ‘corner case’ strategy, one that will only come up for certain people or specific plans that aren’t very common and probably would have tried this method of operation without the Malignant Creep ability anyways.