The war between the three strongest species has ended and while the Overmind is dead his designs for the future continue uninterrupted.
Kerrigan has been infested as planned and stands ready to lead the swarm against the hybrids, but lingering traces of Amon's influence remain within her and she is far more aggressive then was planned. While she is powerful she may end up making an enemy that could slay her before she has a chance to fulfill her role, even the Overmind himself wasn't invincible at the end of the day.
Thankfully for the Zerg the Overmind has more then a few backup plans in place.
Which one are you?
You are a life form designed to work with Terran essence, created back when the Overmind had tried to assimilate the Terran's and re-purposed for a new calling afterwords.
Pros: You have a starting base, ability to mix technology and biology.
Cons: You units are initially weak due being basic infested terrans, expect Kerrigan to take interest in you once you hit the upper tiers and either try to force you into the main swarm or kill you and take the blueprints for your work from your rotting corpse.
You where created to do what the Zerg do best, swarm and overflow the enemy with sheer numbers, none shall stand in your way.
Pros: You get Zergling's for free, bonus to research that lets relates to swarming the enemy with superior numbers.
Cons: Ultralisks cannot be taken as a starting unit, massive penalty to creating giant fighters.
You where made to overwealm the enemy with sheer strengh, you may not be the most elaborate of the Zerg but you know to hit the enemy were it hurts.
Pros. Start with Ultralisks, bonus to researching giant fighters.
Cons: Penalty to working with smaller units.
You are hidden away on an ocean planet, adapted to taking advantage of the life found within.
Pros: High chance of encounters strange life, near monopoly in your home environment.
Cons: Tend to favor other water planets.
You are adapted to a strange planet full of stranger chemicals and bacteria.
Pros: Lots of fun debuff capible units.
Cons: Much weaker in direct combat otherwise.
Like one of your fellows you are working with a Terran faction, unlike said fellow these Terrans aren't infested.
Pros: You get the UED as allies, not as dependent on hunting for existing essence to get designs.
Cons: The local factions aside from UED remnants really really don't like you thank goodness Kerrigan and the Dominion are around to draw the heat away.
The planet your on is cold and harsh........perfect!
Pros: Tougher units.
Cons: Less units.