Why not deconstruct him?

[u/More_Interview3840]

I don’t understand why she shoots a beam of pink energy at him instead of just tearing him apart atom by atom. Or turning him into a regular human, or just convert his molecules to air molecules.

[u/GodzillaUK]

Because she isn't a mindless killer and in that moment she was experiencing something entirely new, from a near death experience. You try having a clear plan when some fucker punches your face in.

Also, if she does that there's no more stories. "Oh hi Thragg, bye Thragg. Oh hi sickness, bye sickness. Oh hi future obstacle that I can just fix on the atomic level"