This is gonna be a two-shot I think, it's set a while after Isla Yura's party, there's spoiler from chapter 42/43 but other than that I don't think there's anything else.
Also, I went with Florence as the Sinclair girl's name since that's was the name on the gravestone Kevin was in front of when he contracted Albus.
"Damnit all!" Break screamed at the unmerciful heavens that were weeping relentlessly over his blood-stained body. All the sealing stones were destroyed; Baskervilles were everywhere, as were blood, corpses and Chains.
Having heard his scream, a heard of Boojum appeared, only to be silenced by Mad Hatter before the Chain-killer too disappeared returning to its place inside Break as the man fell to his knees, consumed by hacking coughs of blood.
When the fit subsided, Break's breath was shaky, threatening to fall into the same despair as his sight.
"Looks… looks like I really will… die alone…" Break whispered, his words ghosting from his lips into the cold night air.
Falling to his side, Break felt his eyelids slowly close as he finally became deaf to the world and let it slip away.
I… I wish I'd never succumbed to contracting Albus… maybe then I could have been of more use… maybe I could have saved that little girl from a similar fate…
When Break opened his eye it was to see a figure, no a skeleton, draped in dark blue robes bearing a crest he did not know, sat on a scythe.
"I am Fest, one of the 07 Ghost. In exchange for housing me within your body the Chief of Heaven will grant your wish," the ghost stated.
Despite the heaviness of his body, Break forced himself to nod, and his hand to move, to touch the ghost, that was how one contracted wasn't it? A handshake, an exchange of blood, something, anything than just lying in a pool of his own blood, cold and more tired than he'd ever been.
Break could have sworn the ghost smirked before his vision was lost once more and Xerxes Break faded into oblivion.
"K-Kevin? Are you alright?"
"…Huh?" Break blinked his eyes open, hissing slightly as sunlight assaulted his vision, "Wh-what happened?"
"Y… you collapsed. I was afraid you'd died too Kevin," the girl before him mumbled, her eyes brimming with tears, and suddenly it clicked, the girl was Florence Sinclair and he was Kevin Regnard once again.
"I thought you'd left me, and that I was going to be all alone," the girl whimpered and Kevin brought his arms up, wrapping them around Florence and pulled her to his chest in a hug.
"No Florence-ojou-sama, I will always be here for you."
It was a moment Kevin remembered well, standing before Florence's grave, damning anything and everything to the deepest bowels of Hell. Now however, Kevin looked sadly upon the stone that was as cold as his body with its unbeating heart. Just as before his Milady had died of an illness, his being there hadn't made the slightest difference, even if she hadn't died alone in the hospital this time.
"Do you want to change the past?"
Kevin started, spinning to his feet, why is Albus here?
"N… no, I don't."
"They didn't need to die. The Will could even save that girl-"
"LIES!" Kevin yelled at the red eyes boring into him from the shadows of Abyss.
"Well then, forget pleasantries, the Will wishes to meet you. And you will come."
"Arg!" Kevin grunted as chain links shot out and wrapped around him, binding him, before dragging him into the darkness. The crack in the sky sewed itself shut after the young knight and uncontracted Chain disappeared inside its depths.
"Ah, you've arrived," Alyss said, turning to her 'guests'.
Sitting up slowly, Kevin sighed inwardly, praying this wouldn't end the same way as last time. There were things he now knew he shouldn't do, and agreeing to the Will of Abyss' wish was defiantly something he shouldn't, the deep engraving on his hand was proof of it.
"My name is Alyss, what's yours?" the girl asked.
"Kevin Regnard, it is a pleasure to meet you Alyss," Kevin answered, always the dutiful gentleman.
Alyss laughed, "My so polite, usually the people who come here are either out of their minds or just want me to grant their wish."
Kevin smiled softly, "My wish was already granted long ago, I have no need of a chain."
"Oh," Alyss said, her eyes widening, "Then perhaps you could help me."
"…Ah…" Kevin breathed shakily, the same pain from his memories resurfacing as Alyss once again placed her fingers in his left eye, swiftly removing the red orb from its socket.
"… ha… ha… !" falling to his knees, Kevin put a hand over his bleeding socket as though doing so would lessen the pain.
"What a beautiful colour," Alyss complimented holding his eye aloft.
"What are you going to do with it?" Cheshire questioned as dolls moved toward Alyss, taking the eye to clean it.
"Give it to Cheshire of course," Kevin wasn't sure what possessed him to do so, but he spoke the words along with the Will of Abyss, causing her to start and stare at him.
"How did? Wait. You've been here before," Alyss accused.
"Yes," Kevin admitted, "But that time I was contracted to Albus and I killed many people in a pathetic attempt to save the Sinclair. I later realised it was unavoidable and I suppose now you could say I'm having a do-over."
"Impossible!" Alyss yelled childishly, before clutching her head and screaming in pain.
"What did the stupid human do to Alyss!" Cheshire yelled at Kevin who glared at the catlike Chain.
"It's Salbier," once again he and Alyss spoke together, causing Cheshire to panic and raise his claws.
"WHAT ARE YOU DOING TO ALYSS!" he yelled charging at Kevin.
Not truly aware of what he was doing, Kevin swung his arm diagonally in front of himself, his palm facing Cheshire. Strange letters appeared out from seemingly nowhere, encircling Kevin and deflected the Chain easily.
"I'm not doing anything Cheshire, this is the Tragedy of Salbier, Vincent has opened the gate to Abyss and all of Sablier is falling inside," Break said flatly, done with trying to remain Kevin Regnard.
"V… Vincent?" Cheshire said stepping back as it remembered how the child had so viciously stabbed its eyes out with a pair of scissors.
"GET OUT OF MY ROOM!" Alyss screamed. Turning, Break saw that the object of her anger was none other than the Sewer Rat himself. Moving back to the furthest wall, Break watched detachedly his hand still covering his empty eye socket, silently marvelling at the attention span of both Alyss and her precious Cheshire.
Soon the room they were in became unstable and Vincent and Gilbert were sucked deeper into the Abyss or kicked out at a random point in time, Break didn't know which. All he focused on was getting to Alyss.
"I'm sorry," he said softly as he sat on a piece of the room that hadn't turned to dust yet.
"W… what do you need to be sorry for?" the girl blubbered, turning to face him from within Cheshire's embrace.
"That I am unable to help you. Perhaps now all the Sinclair are deceased I should find a church and try my luck there. That way I could pray for you and them."
Alyss laughed a little, hiccupping with her tears, "You're a strange man, not even afraid of being sucked into the lower levels of Abyss. You haven't even asked anything of me yet."
"Well how about this then: since you took my eye I'd be very thankful if you could let me out of Abyss ninety years after the Tragedy of Salbier."
"Just that?" Alyss asked unbelievingly.
"Yes, that's all I'd like."
Alyss stood up, her tears drying as she stood before Break, "Alright then, I'll grant that wish." Taking Break's chin in her hand she leaned forward, placing their lips together softly before the floor below them crumbled and they fell in opposite directions.
I hope my switching between Break and Kevin didn't confuse you, on the plus side, the rest of the fic will just use Break now.
Also... I couldn't help the kiss - I support too many Break pairings.