This quirky ability functions like nothing before and like very few things in Heart of the Swarm. Costing 50 Energy and lacking any cooldown at all, it causes Kerrigan to dash towards a target point, up to a distance equal to her unaltered maximum attack range. She will alter course around buildings and other solid objects (thus not traveling as far), but passes directly through units both friendly and enemy. Any enemy unit she passes through while dashing takes 50 damage, a respectable chunk of Life and enough to kill a fresh Marine or Zergling in one shot. Additionally, just having this ability causes Kerrigan to move 30% faster, letting her keep up better with middling-speed Zerg units.
The speed alteration can be a detriment to Kerrigan’s function if you’d rather keep her with your ranged units in the back, but that’s hardly an issue given that this is clearly a close-combat oriented button and you probably won’t be interested in it if you don’t intent Kerrigan to be at least close to if not in the front line of combat. There can be occasional ‘oops’ moments as a result of Kerrigan’s final positioning, and the inability to use the attack to damage or pass through structures can get annoying, but as long as you still have 50 energy left you can easily remedy that by having Kerrigan dash again- forward, back, or laterally is up to you.
This power has a considerably less utility nature than Crushing Grip, and while it does require management it works well even without the kind of quick targeting needed for Crushing Grip. The movement boost effected by the dash can be useful as well as the speed increase, which can often make it more useful than Chain Reaction even when you don’t actually have Kerrigan use the Psionic Shift power. The area of effect that the dash covers is, while curiously shaped, quite large and the overall damage dealt out is often quite worthy. This can also pair amusingly with Leaping Strike, letting Kerrigan pounce a backline unit and then charge back through the enemy front lines into the midst of friendly units and thus greater safety. The range of it actually makes it considerably nastier against short-range units like the Firebat, Reaper, Stalker, Sentinel, Marine, and Marauder, who all often lurk in the middle of its range or at its far reach as part of their method of protecting themselves.
If you like keeping your Kerrigan in close range and don’t mind adding a button to her control panel, this is a very solid ability choice. Micromanagers will most likely find Crushing Grip to be of more overall utility, though, no matter what range their Kerrigan functions at.