Two Weeks Ago
The rain beat hard outside their cave. Brimstone cooked some wild vegetables over a fire while Rosewood labored over a chunk of Rockhoof Obsidian. She sliced a small layer off of her current blade, held it up to an empty slot on Brimstone's leather armor, and then sliced off a little more.
And next to them slept two of Celestia's guards.
Brimstone's wings drooped as he continued stirring. The sharpened stick he used scraped against the bottom of their scavenged pan.
Rosewood cleared her throat and spoke slowly. "So… have you always been able to do that?"
Brimstone took a shaky breath and mumbled. "It… just happens."
She looked between the sleeping guards and Brimstone. "Seems useful."
"It's not." He stirred the greens, barely moving his hoof. "It's a curse."
Rosewood shrugged and resumed her work. "Well, I'm grateful for it, whatever it is. We wouldn't have made it this far without it."
Brimstone's eyes furrowed. "We shouldn't have to rely on it."
With practiced hooves and a sharp stone, Rosewood traced a large chunk of obsidian, then brought her tool down onto it, cleaving off a perfectly sharp knife edge. "I don't see why not. You haven't lost control yet."
"Yet," Brimstone growled. He looked over to see Rosewood flinched, then sighed and recollected himself. "Excuse my outburst. It is just that…" He looked out into the rain. "I saw father wield these powers. I know what it can do to ponies, and sometimes, it is so easy to let it… take over."
"You know what it can do to ponies? Ha!" She filed at the sides of one of the blades, then snapped it into Brimstone's wing cutters.
Brimstone raised an eyebrow. "I have hurt many, many ponies before. Yes, I know–"
"And you weren't even trying to." Rosewood set down her work and stomped over. "Brimstone, I've worked under Sombra for decades. He absolutely raged in the weeks after you left, and most of the staff still has the scars to prove it."
Brimstone quickly looked her up and down. "Not all of them, it seems."
"Yes. He spared me." Rosewood's face softened. "Because you asked him to."
Brimstone paused, then stirred the vegetables again. "I am sure I do not know what you mean."
"Why do you think I sought you out?" Rosewood sat next to him. "Sombra's a monster, but he's always been fond of you. You asked him not to harm me, and so, he didn't. Not in those days, at least." She looked at the ground. "But he did terrible, terrible things to the other slaves. Brimstone, I know what we're up against, and if you can use the same power to help us, then by Luna, use it. It'd be irresponsible not to."
Brimstone removed the food from the fire. "Rosewood, I appreciate your insight, but there is nothing more to say." He glanced at the sleeping guards. "I will not misuse the power to hurt ponies, and that is all it seems good for."
Rosewood shrugged. "You saved us from the guards. Isn't that a good use for it?"
Brimstone glared at her. "No, because they are likely to be fired for failing."
Rosewood rolled her eyes. "But you didn't hurt them. Brimstone, you don't have to use the powers the way Sombra does. Are they dangerous? Sure, but they're a tool, just like everything else." She looked behind her and grabbed an obsidian knife. "Like this. I could plunge it into your stomach right now, but I'm not going to. I'm going to help you use it to free an entire kingdom. So is it really a bad tool?"
Brimstone paused, then glanced around. "I don't know how to free the empire."
Rosewood softened again. "Yes, you do."
"I cannot kill him."
Rosewood set the knife down slowly. "I hope you don't have to. I hope it doesn't come to that, but I know Sombra, and he might force you. And if he does, you'll need to know how to defend yourself." She nodded at his wings. "You already know how to use those. It's just a matter of learning to fight with them."
Brimstone glanced at his wing blades. They looked so much more menacing with Rockhoof's Obsidian on the ends. He nodded. "How could I even learn?"
Rosewood chuckled bitterly. "Well, you'll get plenty of practice in the Fields of Eternal Winter. They're only a few days away."