Heart of the Swarm Campaign- Zeras: Supreme

With Kerrigan now taking a place as a primal Zerg herself, and essentially equal to the primal pack leaders, she must now prove herself and defend the swarm- by slaying those pack leaders that would see her undone.  Your rewards for completing this mission are high- five levels for Sarah, and the evolution mission for hydralisks for you- and include a bonus objective that will net you a whole four additional levels for Kerrigan.

For this mission and this mission alone, you do not get to choose Kerrigan's abilities.  You are shown the three primal pack leaders you have to face here- and then given only Kerrigan to face them with.  Sarah starts off with only the ability to burrow into the ground- though this will soon be augmented.

From where you begin, you will need to move to the Northeast.  You will find your way blocked by a chasm, with a primal hydralisk on the far side.  This is when Abathur reveals Sarah's first new ability, Leaping Strike.  Both an offensive and travel ability, this allows her to cross a decent distance near-instantly, regardless of terrain interruptions, and direly damage anything at her landing point.  You will need this to continue traveling around the map, so take advantage of the automatic hotkey.  The second leap will reveal a cluster of primal zerglings, which can be destroyed by the next ability Abathur explains, the Psionic Dash.  This causes Sarah to streak forwards in a sort of glide, dealing a crushing blow to any and everything she passes through/over/beside.  Crossing the next gap will allow you to reach an island with a Xel'naga relic upon it- collecting four of these is your bonus objective, and each will grant an additional level for the Queen of Blades.

Crossing to the next island reveals several primal roaches fighting with a cluster of hydralisks.  These roaches are allies of Dehaka, the primal zerg who has joined Kerrigan on her leviathan.  Once the hydralisks are slain, Sarah gains her third ability- Mend.  Use this to keep the units you gather on your mission in shape for combat.