The creature, risen to its full height again, stared at Shining as its horn grew brighter with energy. The unicorn didn't move. There was no point in moving too soon, no real point in doing it until he was sure he'd get to dodge the blast by doing it. Not at that distance at least, not while he wasn't moving already, not with the creature's sight already on him. "Do you have a plan?" he asked to Cadence, at his side.
"No," the alicorn admitted. At least with Sombra they'd had places to hide and catch their breath. And though the pony in front of them wasn't as powerful as the unicorn had been, it seemed far more resistant to magic in general. Not so much capable of withstanding its forces as downright unaffected by it, though a fair degree of resistance was there as well given what it had survived.
"Right." Shining swallowed. His legs tensed. His breath became deliberately mechanical, a pause after every inhale as he held the air in, a pause after every exhale. His head went through thoughts faster than his mouth could spell them out. Every idea he came up with he threw out. No reflecting the spell with his magic, no doing it with any material surface and no making a shield out of that either. Too much effort to cut off a big enough portion of the ground to do anything significant, not enough time and not enough magic for it. Teleportation? With how quick they'd need to be and how complicated that was, physically jumping out of the way was almost guaranteed to be safer, unless the spell carried a big enough explosion along. Which they wouldn't know until it hit the ground, or them if they were unlucky.
"Should I tell them to run?" Cadence asked. She was talking about the other guards there around them. Shining's answer would have been that she should have run along with them, and Cadence would have agreed to it after a moment of thought. She wouldn't have been happy about it, but she would have agreed. She would have been much less happy about it later on, if things went bad, and she'd have started to regret her decision. Shining knew it would go like that, and she knew it too, even if she chose not to think about it.
None of that came to pass. What came to pass was a spear through the creature's chest. Silver from end to end, it pierced its flesh like a hoof tearing through wet paper, and remained lodged there. The creature screamed in pain, for what its dysfunctional vocal cords and lungs allowed it to, and all the energy it had built up in its horn flared upwards like a geyser as control over it was lost.
Shining and Cadence looked around, expecting to see Luna magically healed and standing on her hooves again. When their eyes found her, she still lay over the back of the only other unicorn with them, still unconscious. What else they did see just a moment later was a blue and rainbow blur, streaking towards the creature and pushing the spear fully through it before flying away again.
Rainbow Dash landed at their side, her silver armour spotless despite the blackened winds she flew through. "Need help with that?"