Sarah Kerrigan

Neutralized because, despite being really popular, and despite fitting oh so many archetypes, the Starcraft fanbase is entirely dominated by straight men, and the straight men really want to fuck her.

Basic Information
Sarah Kerrigan displayed strong psychic powers at a young age, which meant she was forcibly conscripted into a military program to become a deadly psychic assassin, with her personality and free will being supressed by neural implants and drugs. She was rescued by a rebel leader, and then felt indebted to him, up until he successfully overthrew the oppressive government they were fighting, because he left Kerrigan to be devoured by the terrifying hive-minded aliens known as the zerg. Thing is, the zerg did not kill her. Instead, they turned her into one of them. After this event, she proceeded to kill a lot of people, and ended up becoming the leader of the zerg. As their leader, she continued to be ruthless and vicious and widely feared, but eventually it turned out that she was the only thing keeping the universe from being completely destroyed, due to... look, it's very complicated. Her page on the starcraft wiki is absurdly long and very full of spoilers. Just know that she was an assassin, and now she leads a swarm of all-devouring alien bugs.

Villain
Supporting antagonist in Starcraft, one of the main antagonists in the Brood War expansion (or protagonist, from the zerg's perspective). One of the two main antagonists of the Wings of Liberty campaign in Starcraft 2.

Girlboss
She's killed billions, and the fanbase loves her for it.

Power
Even without the massive legion of monstrous aliens at her beck and call, Kerrigan is an absolute nightmare to face on the battlefield.

Dominating
She's the leader of an alien hivemind that regularly captures and infests (or simply kills) basically anything they can get their hands on. Even as a human, she was a powerful psychic who could read peoples' thoughts.

Intelligence
In sharp contrast to the typical zerg player's strategy of just throwing a fuckton of units at enemy until enemy die, Kerrigan herself engages in a lot of villainous masterminding, forging alliances of convenience that end in bitter betrayal, infiltrating enemy bases to tear them apart from the inside, one time even employing a spy, and just generally manipulating situations to her advantage and being sneaky-sneaky. Must be all those years working as an assassin.

Duality
Human Kerrigan vs Infested Kerrigan. The fandom isn't really as interested in exploring that theme as the writers are, though.

Monster Features
Bony bat wings, sharp claws, weird carapace skin, weird tentacle hair, biological high heels on her feet for some godforsaken reason... also, she can regenerate limbs freely, and if she ever dies, she can just reincarnate in a new body thanks to zerg psychic power.

Eldritch(?)
Probably counts? The zerg aesthetic is full of pulsating flesh and tentacles and green goop, and is also very obviously inspired by the xenomorphs from Alien.

Purple
She started out being green, but then turned purple in her 'Primal' form. Notably, art of her infested not-primal form is sometimes both green and purple, which is very odd and an unexplained design inconsistency.

Eye Imagery
They have a really strong yellow glow in most of the artwork, sprites, even some of the ingame models and portraits. Primal Kerrigan loses this quality.

Glowing Neon
Again, the eyes, but also, Primal Kerrigan has little 'veins' of purple lights along her skin and carapace.

Distinctive Voice
There's this very strong filter placed on her when she's infested and it gives her ruthless villainous speeches a very lovely touch of femme fatale.

Knifemurder
She will often go out of her way to kill people, even when it's not necessarily tactically sound. Most alliances with her have ended in sudden and bloody betrayal after she got what she wanted from them. In one short story, she made the particularly sadistic move of letting someone think they'd escaped, before ordering her minions to hunt them down and kill them. Yeah, she's pretty vicious.

Angst
In the first game, she was left to die by the man who had saved her from being what is basically an enslaved assassin. Her bff/bf Jim Raynor angsts about her fate as an infected zerg extensively. Just to hammer in the angst, the supplementary books and comics detail just lovely events from her past, how she accidentally killed her mother as a child, was pulled away from the funeral to be conscripted as a Ghost, how she was subjected to all manner of cruel testing, and who could forget that one classic scene where she was coerced into using her powers by being made to watch a kitten get injected with a tumor-causing chemical, then be ordered to use her powers to either remove the tumor or euthanize the kitten?

Yeah uh. It's a lot.

Power of Love
It's the weakest part of Starcraft 2's narrative, but it is there. Jimmy boy loves his Sarah so much, and him saving her butt is basically what sets her redemption arc in motion.

White
Self-explanatory, look at her human form.