Elphaba was ready to cast the spell. She was just about to do so when she heard that familiar voice. She looked up and saw Galinda free the girl. Oh this wasn't how this was supposed to happen. Elphaba grew even more upset, hating Galinda's interference. This wasn't going to go well from here on out. Not that it was going to be rainbows and sunshine had Galinda not shown up, but things would go far worse than they otherwise would have. She stayed positioned at her Grimmerie, teeth clenched in anger.
"Go away." Because even in her rage and madness, her first thought was for Galinda to go away, go somewhere safe. Though if Elphaba was left to roam wild, no place would truly be safe. And she was giving the blonde one warning before she did something bad. True Elphaba would never forgive herself for what she'd done, nor would she forgive herself for hurting Galinda. But at this moment in time, neither mattered to her. All she could see was what was right in front of her, along with a tinge of red because she was in the throes of rage. A rage that was still quickly building. It was at a level she'd never felt before, even when she'd been under Wrath's influence when the Sins had infected them.
She looked at Galinda, her eyes as cold and distant as they had been when she'd killed that evil witch a couple months earlier. Everything good she'd carefully stuffed deep down inside herself, hiding it from the world. But of course Galinda had to show up, perhaps the only person who could look at Elphaba and know it was all just a cover to mask the pain she felt inside. She had to keep herself steadfast, she wouldn't let herself be snapped out of this. She would stay on this path because this is who she was now. Her friends would just have to accept it. She was the Wicked Witch of the West and she was here to stay. Well, at least until the witch hunters came en masse and killed her. Though she would at least go down with a fight. No wretched little farm girl to interrupt her plans, no escape plan. It would come down to her life or theirs. She wouldn't run, she would stand and fight and the best warrior would win.
But before that, she had to get rid of Galinda. If the blonde wouldn't leave with the one warning, then Elphaba would take things into her own hands and find another way to get rid of her. She was ignoring the voice in her head that whispered to her to stop. It had no power to stop her anymore. And it spoke volumes to her state of mind when she would use violence against her best friend, the one she loved.