I object to your heavy-handed character murdering. You put me in a situation with pretty much no hope, and now you expect me to just roll over and accept it?
Maybe the alicorn could have tried to be reasonable. The illusion didn't vanish unless she got hit, so for all she knew, Night Jewel attempted to humiliate her with a hairbrush. This is kind of ridiculous. In any case, you shouldn't jump straight to "kill off an important PC".
I'm through with this entire setting, I think, unless you decide to be merciful. I am literally shaking with rage as I type this.