The voice snorted, "Be real. I'm not trying to kill you - unlike some people. I prefer finding good uses for them."
Somehow, neither option sounded appealing.

You could imagine McKenna shotting you a winning smile as she clambered in after you. "Eh, we still had three seconds to spare. And, this was way more fun!!!"
McKenna suddenly bumped into you, "As I said, we only have three seconds to spare. This is a time to move fast."

The thing shoves you out the window further, seeming to enjoy calling out 'Don't look at the moon!' in different voices. Snorting, you feel its fingers creep up towards your eyelids. You had a feeling you knew what would come next. He would pry them open.
Then you'd have to look at the moon.

And how is it useful as a weapon?

It cuts through souls. Kills the soul. If I hit your waist with a shardblade your legs would stop working.
It cuts through anything dead, too.

That seems slightly too powerful for this game. Maybe eliminate the 'cut through anything dead' part?

I pry the thing's hands off of me and try to run away, keeping my head down as to not look at the moon.

"Good uses..? I'd much rather keep going the way I was before" I say as I try throwing off this person yet again

So it's simply a weapon of killing things, not a weapon of usefulness.

How bout it can cut thru anything but doesnt cut souls

"McKenna, I'm going as fast as I can," I reply. "We would have more time if you told me about this area earlier."