“Why are you telling us this?” Faust asks, his gun still pointed at their front.

Sol smiles.

“No vampire or vamp hunter can beat me,” he says, teeth sharp in the lamplight. Above them, a pair of moths dance around the light’s glass cloche, their wings flickering desperately in an attempt to get closer to that untouchable brightness. “But while I’m not against getting my hands dirty, it’s better for me to pit you two against each other. I have plans for this city, and another strong vampire settling down in the area will only get in my - in the Corvinus Clan’s - way.”

“So…” Caius says, his mouth dry, gaze flicking between Sol’s face beside him and the gleaming silver barrel of Faust’s gun pointed steadily at them, “the favor you want…”

“Yes,” Sol hisses, the corners of his mouth twisting in a grin, his words ice cold. “Eliminate the throat-ripper for me, please. It’s a winning situation for everyone.”

“I won’t ally with vampires.” Faust bites out. His trigger finger tenses.

Sol stands up again, dragging Caius with him by the neck.

“But you won’t shoot.” He says, crimson hair alight like flame in the yellow light, contrasting vividly against his black cloak. He smiles so largely it crinkles the corners of his eyes - it almost makes him look friendly. “Not while your precious student is under my hand. I can smell the thick scent of worry coming off your skin.”

Caius glances at Faust - oddly touched, even though the man is pointing a gun at the both of them, that his grouchy and standoffish professor would be concerned about him - he sees Faust’s glare only sharpen at the provocation.

“For a supposedly mature vamp,” he says lowly, “you know surprisingly little about the inventions of the modern age.”

He shoots. Caius hears the loud pop echo through the alley, ricocheting against the brick walls and bouncing sharply off the glass windows, as though it’s going to jump straight into his ear and pierce his eardrum. The bullet goes straight into the back of Sol’s hand, the one atop Caius’s throat - and stays there. It doesn’t blast through the skin.

Caius stares at it. With his angle he can’t get a proper look, but it doesn’t look like a regular bullet even from the bottom of his vision.

And then he hears the hissing of frying skin and singing flesh - the sound of acid eating through live tissue - and the acrid scent of necrotization fills the alley and Sol screams. His hand is burning like it’s been splashed with corrosive liquid, the veins bulging and going purple, flesh sloughing off from the inside out, arteries dissolving from the inside.

The condition quickly spreads up his arm. He throws Caius away from him and starts to tear at the flesh of his right shoulder with the cutting and brutal nails that had torn through Caius’s abdomen. Blood runs in rivulets down both of his arms as he rips through his own muscle and sinew, dripping to the cobble from his elbows.

Faust shifts to stand closer to Caius, then shoots again - Sol dodges. Caius scrambles to his feet and pulls out the knife sheathed in the small of his back, feeling its now-familiar weight press against his palm. The silver almost glows white in the darkness. He holds the weapon close to him, settling his arms in a defensive stance, but Sol moves so quickly that he’s almost invisible to the naked eye, even when greviously injured.

Blood drops to the stone floor in great globs, congealing into thick pieces before sizzling away with a terrible smell. Faust shoots four more times, but each bullet misses its mark. Instead of reloading he pulls a silver dagger from his belt, crouching slightly with his arms up, protecting Caius behind him.

There’s a heavy and gruesome wheezing sound, and Sol’s entire right arm finally falls to the ground with the sickening noise of dead flesh.