Sarah Kerrigan is a playable commander in the Co-op Missions mode of Legacy of the Void. She is controlled as a hero unit during missions akin to Heart of the Swarm, and has powerful zerg strains at her disposal.
As a hero unit, Kerrigan is devastatingly powerful, and grows stronger and stronger as upgrades and talents are unlocked. With her attack damage and attack speed bonus maximized, and especially Psionic Shift, Kerrigan can quickly tear through large numbers of weak enemy units, and Leaping Strike can strike down tougher enemies. Leaping Strike also allows Kerrigan to quickly leap into engagements and retreat if overwhelmed, and her ability to leap up and down cliffs makes her very mobile.
Overall, Kerrigan's biggest weakness is a severe lack of crowd control abilities and vulnerability to large number of enemy air units. While her basic attack and related bonuses allow her to hold off handfuls of air units, she simply lacks the control or DPS to handle large forces, as Leaping Strike and Psionic Shift only affect ground units. When faced with a substantial enemy ground force or air force, Kerrigan must use Immobilization Wave to stun them and kill them while they are immobilized; otherwise she had best retreat.
Kerrigan takes 4 min to spawn at her base. If Kerrigan is ever killed, she will respawn 60 seconds later at the player's primary hatchery/lair/hive.
Unlocks additional upgrades for Kerrigan on the evolution chamber. • Upgrades Kerrigan's attacks to deal normal damage to her target and then jump to additional nearby enemies. • Reduces Kerrigan's ability cost and cooldowns by 20%.
Kerrigan is the most beginner-friendly unit of all the commanders. Because the player actually controls Kerrigan, she will become a central unit for much of the early and mid game. She so strong that she can make up for a lot of her unit composition deficiencies. She can easily solo the first 4 waves; during the midgame, she is the cornerstone of her army. Take advantage of the fact that she soloed the early waves to heavily tech at the beginning.
In terms of her available army and related upgrades, the strongest over-arching characteristic is speed. Kerrigan's forces are fast and light, and if the player makes a point of spreading Creep over as much of the map as possible without interfering with their partner, Kerrigan and her army can be a "fast reaction force", focusing on and defeating an enemy wave in one key area then rapidly re-deploying to another. The player should get resource production as strong as possible, get multiple lairs up and quickly replenish lost units whenever necessary; being lighter units Kerrigan's forces will take a notable amount of losses as they go.
Power Set 1: Kerrigan Attack Damage
Full points in attack damage significantly increases Kerrigan's effectiveness vs. air units, which are Kerrigan's greatest weakness. Kerrigan's energy regeneration is never a problem with her level 15 ability.
Power Set 2: Combat Unit Vespene Gas Cost
Full points in cost reduction means hydralisks cost 35 gas.
Power Set 3: Expeditious Evolutions
Faster and cheaper upgrades for Kerrigan and her army works great, no matter what the strategy is; Ability Efficiency's 200 200 120 upgrade at full points becomes 80 80 48!
Kerrigan takes the field herself as a hero unit, and is very powerful. Her leaping strike is best used to rapidly destroy hybrids and other similarly powerful enemy units, while psionic shift provides crowd control against swarms of 'light' units. Assimilation Aura provides extra resources and its efficiency will improve as the difficulty increases because there will be more units that to kill; its a short cooldown, so it should be used frequently, especially when engaging large numbers of enemies. Immobilization wave will allow her and her ally to attack enemy bases or face dangerous waves safely; it also has a short cooldown time of 3 minutes (with improved capacity efficiency, it will only take less than 2:30 minutes cooldown) so it can be used frequently. As Kerrigan levels up, more abilities and upgrades become available to her, some requiring mutating at the evolution chamber. All of these should be mutated as resources allow, since good use of Kerrigan is critical to success.
Kerrigan's core offensive primarily consists of zerglings with smaller numbers of hydralisks or mutalisks for anti-air support; hydralisks are faster and cheaper to build than mutalisks, but mutalisks have superior damage output once Kerrigan reaches Level 11 and unlocks their upgrades at the spire. At higher levels once her ultralisk upgrades unlock, consider adding a few of them to her unit composition to support zerglings. Lurkers and queens are only useful for "defense maps" against terran and zerg, but against protoss are of limited use. Even against terran and zerg, lurkers should not be mutated in large numbers; only several are needed to defend ramps and other choke points. Queens should still be used for Spawn Larva and creep tumors, though. Brood lords are good for overwhelming enemies if the player has a small ground army, but otherwise mutalisks, fully upgraded, out-damage them.
Keep Kerrigan close to her brood to aid them with an overseer hovering above her; and have her tank hits while her other units support her. Micro her expensive ultralisks and brood lords to avoid losing them recklessly, and keep replenishing her more expendable forces as needed. Good micro of Kerrigan is critical to victory, so have other units just attack move while focusing on controlling her directly and make the most of her abilities. With the proper unit composition, Kerrigan and her brood can easily overwhelm enemies and do well with most any type of map.
Kerrigan's nydus worms should also not be neglected. Once she gets the Omega Worm upgrade, she can almost instantly transport a massive army to the front lines, quickly overwhelming any defense. Though she cannot make good use of it on all maps (i.e. Oblivion Express, Temple of the Past), it is still extremely useful to help put an entire army right in the middle of an enemy base, especially if the main ramp to said base gets clogged with ranged units such as goliaths and dragoons.
Kerrigan's exceptional power as a hero unit should be taken into account when considering the formation of her army. A player investing primarily in zerglings while building more powerful mutalisks or ultralisks will rapidly find themselves exasperated by how quickly the zerglings fall against enemies, even with Kerrigan soaking up the majority of enemy fire. This can quickly lead to Kerrigan's death on higher difficulties, making her early game strength inaccessible until she resurrects.
Artanis is an effective teammate for Kerrigan. Shield Overcharge and Guardian Shell helps to protect and prevent expensive losses with mutalisks or ultralisks. On higher difficulties, area-of-effect abilities like psionic storm and hunter-seeker missile are common from enemies, and Kerrigan's mutalisk swarms can be crippled quickly. Artanis' Guardian Shield will protect them from these abilities, and give the Kerrigan player time to retreat her mutalisks so they can regenerate and return to battle.
Karax is an effective teammate for Kerrigan. Chrono Boost accelerates the mutation speed of Kerrigan's higher-tier units and the many upgrades they need to be effective. He can also use colossi and immortals to support Kerrigan's units with siege or anti-armor capabilities as needed, and his energizers with chrono beam can rapidly buff her stronger units to very dangerous speeds.
Vorazun is an effective teammate for Kerrigan. Black Hole can set up enemies for Kerrigan's mutalisks, and they can combine Time Stop and Immobilization Wave for a prolonged stun of enemies. Vorazun also powers up Kerrigan's lurkers with her passive talents to buff cloaked and burrowed units. Vorazun can make up for Kerrigan's anti air and detection weakness with corsairs and oracles. The teleport to a dark pylon allows Vorazun to quickly return to defend allied bases if cloaked cannons are unable to cope.
Alarak is an effective teammate for Kerrigan. She has a strong anti-air presence with hydralisks and mutalisks, while Alarak provides crowd control she lacks with ascendants and vanguards. Kerrigan's raptors and upgraded torrasques can bypass Alarak's supplicants to get into melee range easily, while hydralisks fire from behind them and ascendants from behind them, thus their armies synergize perfectly in battle. Havoc support to increase their attack range and damage to select enemies is also of great benefit, on top of negating the necessity of overseers. Immobilization wave will also minimize damage received, keeping supplicants in high numbers much longer. Together, Kerrigan and Alarak can decimate enemies as hero units, especially when both are level 15 at which point all of their ability cool-downs are either super fast or nonexistent. Omega worms are also a perfect alternative for rapid army transition without the Death Fleet to teleport units.
Fenix and Kerrigan have mediocre synergy. While the resource boon helps Fenix, the larger gate for Fenix's army is usually the time it takes for him to construct an army. Both have a strong early game and rely on hero units to take early waves, with Kerrigan having a bit more reliable defense against air. The benefits of Fenix's recall overlap with Kerrigan's ability to use omega worms for full map mobility. In the late game, the two armies work great, and zerglings and ultralisks are able to soak damage while Fenix's larger army of colossi, carriers and adepts or immortals can choke up enemy attacks. Immobilzation wave allows Fenix to push into tough positions and wipe them out with ease.
Raynor is an effective teammate for Kerrigan. Raynor's infantry forces mesh well with Kerrigan's zerglings and ultralisks, who can leap/burrow charge past Raynor's infantry to reach targets, and ultralisks provide damage tanking to defend Raynor's fragile marines. Raynor further has medics to heal Kerrigan and her brood, making them a dangerous combination.
Swann is an questionable teammate for Kerrigan. Swann's reliance on mechanical units clashes with Kerrigan's biological zerg; they have few synergistic abilities to directly support each other. Swann's vespene harvesters are invaluable; allowing Kerrigan to upgrade and train mutalisks and ultralisks in large numbers. Swann's goliaths and thors are superior to Kerrigan's hydralisks as ranged support, so the Kerrigan player is better off building an army to supplement Swann's ground forces. Additionally, Kerrigan's Omega Worms can help Swann's slow army reach the front lines much more quickly.
Nova is an excellent teammate for Kerrigan. as her Assimilation Aura will let her give Nova precious resources to get off the ground. Her Malignant Creep can also help Nova's army in sustaining itself, while Kerrigan's zerglings and ultralisks tank damage for Nova's troops. The creep can also help Nova by providing vision, letting her use airstrikes and nukes more easily. Immobilization Wave can set Nova up for a nuke, and Nova can provide detection so that Kerrigan doesn't have to get overseers. Kerrigan's nydus worms create some redundancy with Nova's Tactical Airlift.
Zagara is a questionable teammate for Kerrigan. Everything Zagara's units can do, Kerrigan's units can do better and they will generally emerge with far fewer casualties. Even Zagara's banelings and scourge pale against Kerrigan and her upgraded mutalisks. However, Zagara's queens can use Inject Larva on Kerrigan's hatcheries to give them extra larvae, and Zagara can still benefit largely from Kerrigan's Malignant Creep. Mass Frenzy can also still be very helpful for Kerrigan's units.
Zagara can offer Kerrigan early crowd control with Banelings, as well as mutalisk and ultralisk support via corrupters and aberrations. But ultimately Kerrigan's army will outstrip Zagara's forces by the end of the game. With full mastery, Kerrigan exceeds Zagara even in the cost saving area: Kerrigan's ability to lower the vespene cost for her units and upgrades provides her with a tremendous advantage.
Abathur is an excellent teammate for Kerrigan. Kerrigan herself can cover the early game with little assistance from Abathur. This allows Abathur to spend resources on teching up rather than focusing on early game defense. Kerrigan's assimilation aura allows Abathur to gain a large resource boost. Malignant Creep can benefit the overall speed and performance of Abathur's army, and allow him to respond to threats faster. In late game, Abathur can provide a frontline army while Kerrigan supports from behind.
Stukov is an excellent teammate for Kerrigan. Kerrigan's Malignant Creep and Stukov's Infinite Creep greatly augments both forces to close greater distances. Kerrigan's early-game dominance allows Stukov to fast-track his research. Stukov's late-game infested are a protective screen for lurkers and hydralisks. Stukov's cooldowns aid quick strikes done through Kerrigan's Omega Worms. Stukov's mineral heavy forces are greatly supported by Kerrigan's Assimilation Aura, and Immobilization Wave allows infested forces to encircle enemy defenses unopposed.