This is how Twilight vs. the Symbiote goes in My Little Pony: Equestria Girls: Rise of the Symbiote.
[The Symbiote runs and stops when he sees Flash Sentry coming. The Symbiote prepares to throw him out the nearby window when Twilight, in a blind rage, sees this and screams in anger as she runs forward, and attacks the Symbiote, beginning the last battle between the two of them]
[Twilight tackles him]
Twilight Sparkle: I'LL KILL YOU!
The Symbiote: Rise above this. His love for you means nothing.
[She kicks him]
The Symbiote: His feelings for you give you strength. Embrace it.
Twilight Sparkle: I WILL KILL YOU!
The Symbiote: [losing patience] If you wish join the boy, so be it.
[He pushes her off]
The Symbiote: He loved a she-demon. He vould have never loved you.
Twilight Sparkle: YOU WILL DIE WHERE YOU STAND!
[The Symbiote grabs Twilight and throws her from the platform. Twilight manages to grab onto the edge of the platform, and the Symbiote attempts to dislodge her by throwing balls of magic at her repeatedly. Twilight manages to catch one of the the balls on its fourth throw and tosses it back at the Symbiote, severing his right hand. The injury however, only momentarily distracts the Symbiote, who, after missing Twilight with a backhand punch, uses magic to push her across the platform and attempts to crush her with one of the pylons. Twilight barely manages to hold it off herself, and raises another pylon from the platform. The Symbiote glances over at the second pylon, and Twilight uses the distraction to toss the first pylon off herself. Using her magic, she causes the remaining pylons to release a huge amount of electricity, which she then absorbs and uses to blast an incredible amount of lightning at the Symbiote, finally subduing him. The Symbiote collapses on one knee as Twilight approaches him with a sword]
Twilight Sparkle: You've taken everything from me!
The Symbiote: Flash Sentry and your feelings for each other are not real.
Twilight Sparkle: THEY ARE REAL TO US!
[Twilight prepares to take the killing blow when Sunset Shimmer and the girls arrive]
Sunset Shimmer: Wait!
Twilight Sparkle: You want him dead as much as I do!
Sunset Shimmer: Yes, but not yet! Not until he's told us what his plan is!
Twilight Sparkle: You want to take him prisoner?
Sunset Shimmer: To a safe place where we can interrogate him, put him on trial for crimes against the people of this world. And then we'll execute him, to show everyone in this world that we don't need to fear him any longer.
Twilight Sparkle: If I let him live, he'll haunt me forever.
Sunset Shimmer: He is the only one who knows fear. He can't tell you if he's dead.
The Symbiote: Strike me down. It is your destiny.
Sunset Shimmer: She won't. Not yet.
The Symbiote: This is your destiny.
Sunset Shimmer: [to Twilight] Think of what could happen if you strike him down in anger. We need him alive.
[Twilight calms down and walks away]
[Sunset and the girls get things to hold the Symbiote with]
[Twilight continues walking when Flash shows up]
Twilight Sparkle: What do you want, Flash?
Flash Sentry: I just wanted to say, great job at not giving in to your anger.
[Twilight and Flash smile at each other and kiss]
[Twilight visits the Symbiote in jail]
Twilight Sparkle: I let you live. You tell me I'm a part of you, but I chose to spare you. Maybe Sunset is right. Maybe this is all a trick, a way to get me so confused that I'd forget who I am and become your slave again, but either way... I let you live. I've finally broken your hold over me.
[Twilight turns to leave when the Symbiote looks up]
The Symbiote: As long as Flash Sentry lives, I will always control you.
[Twilight grins at him, shakes her head, and leaves]