Regrets - Castiel's past is unchangeable, but it still hurts more than one angel can bear.

It was meeting the young nephilim that did it.

She recognized Castiel; how exactly, he'd never know. It didn't really matter. Her blade was drawn and before he could blink she was on him, snarling and stabbing with a wild light in her eyes. The angel was caught completely off-guard, and though he tried to dodge, the first few blows sliced into him.

Now bleeding, in pain, and utterly bewildered, Castiel retreated several steps and drew his own blade in preparation to defend himself. He thanked his Father that this crazed woman had at least chosen to attack him in a vacant lot where no innocents would get hurt. Then again, no one was going to intervene.

"Who are you?" he called as the young woman circled him, murder in her expression.

"What's it to you?" she spat. "All you need to know is that I'm the one who's going to kill you."

"I prefer to make the acquaintance of my enemies before they kill me," Cas said. "I feel it's only polite."

The nephilim lunged at him again, angel blade swinging in a deadly silver arc. Cas paried and took another step back. Her combat style wasn't disciplined, she left herself open in her eagerness to attack, but she was very fast. He considered flying out of here, but at such close range she could probably use her powers to stop him. Besides, he wanted to know what this was all about.

A growl issued from the throat of his opponent. It was a deep, animalistic sound that should not have been made by a slender, delicate-looking girl. She lunged again, swiping the point of her blade at every part of him she could reach. "You-killed-my-father!" she snarled, punctuating each word with another vicious blow that Cas barely deflected. He kicked her legs, a low blow that bought him only a few seconds respite.

"When you were purging Heaven," she continued, regaining her balance and taking another shot, "you slaughtered hundreds. Thousands. One of those you killed was my father, an angel named Arael."

It suddenly made bleak, bitter sense to Castiel. Back when he'd consumed the souls of Purgatory, he'd thought he was defeating his enemies. In reality, he'd only made more. All that destruction, all that death, and he'd accomplished nothing. It was the most unjustifiable atrocity he'd ever committed. "What I did was unforgivable-"

"You're damn right it was!" She was crying now, crying as she attacked him more and more wildly. "How many did you kill, Castiel? How many lives did you take in order to satisfy your own lust for power?"

"I never intended for it to go so far." Cas flinched at the weakness of his excuse. He hated what he had done, could still not look his brothers in the eyes two years later.

"Because intent is what matters, of course!" The nephilim laughed, tears still streaming down her face. The effect was something mad, twisted, and piteous. Cas lowered his blade.

"I don't want to hurt you."

"You should have thought of that before you murdered my father and a thousand more." She leapt at him one final time, and he tried to raise his blade to defend himself, tried to disarm her, tried to do something but his knife was in just the wrong place and he wasn't fast enough and the light and the blood and-

-And he was far away from that empty lot, surrounded by dusty road and grazing cattle. Texas? He did not know, nor did he care. He had flown at random, because he had seen the light pouring from her eyes as his blade cut into her heart. He had felt her blood, hot and slick on his hands.

He'd killed her.

Like he'd killed her father.

He didn't know her name, he realized numbly. He knew her father was Arael, but he couldn't recall a face to go with that name nor a name to go with the girl's face.

And there was the shame, that horrible, crushing shame that hounded him ever since he'd released his captive souls. It never completely left him, but he'd been able to keep it at bay. Until now. Until he'd been so forcibly reminded of his past.

He stumbled in place, dizzy, as the memories assaulted him. Images of corpses, a thousand of them, blackened wings stretched out in repose, crashed before his eyes. In his mind, every one of those thousand faces was twisted in accusation. Every one of them had a name, usually a name he'd tried to forget. Maybe all of them had children secreted away somewhere as well. Maybe even now, a thousand grieving nephilim were calling for the blood of Castiel, the blood of the angel who had murdered their parents.

His lieutenant had tried to warn him. Dean had tried to warn him. Everyone who knew the plan had told him to find another way, everyone except Crowley, who'd egged him on.

He'd trusted the advice of a demon more than that of Dean Winchester. He'd allowed himself to be corrupted and twisted in so many ways it hurt to think about. And he had killed a thousand angels.

Did he scream? The empty air must have eaten the noise.

The Texan countryside vanished, replaced by hardwood floor, marble, and bookshelves. He fell to his knees in the bunker's library, because it was too much and it was too much and it was too much. "Dean," he said. Or did he whisper it? Shout it? Think it?

The next few minutes were a blur. Time didn't really exist properly, not until Dean came through the doorway and saw the angel kneeling on the floor.

"Hey. Hey! You okay? You look like- Oh hell, is that blood?"

His hands were surprisingly gentle as he uncurled the angel and looked him over, worry creasing his brow. "Shit, Cas. You get into another fight with Crowley or something?"

Cas shook his head, then kept shaking it because Dean needed to know that things were not alright. "Nephilim," he croaked. "I killed her father. Then I-" He swallowed. "Then I killed her. Just now. I didn't mean for it to happen." He looked at Dean in desperation. "I didn't mean for any of it to happen." And to his surprise, he felt his itching eyes begin to run.

Dean looked alarmed to find himself suddenly holding a crying angel. "Woah, woah, we can sort this out. What are you saying?"

"They were my family, Dean," Cas choked out. "I've committed one thousand counts of fratricide."

The hunter paused. "Oh," he said. That was Dean Winchester, confronted with the confession to a thousand cold-blooded murders. Oh. Then, "Listen, Cas...it's awful, okay? I agree. And you feel really bad about it. But you can't fix it by beating yourself up." He awkwardly patted the angel's shoulder. "Trust me, I have experience with this."

Cas tried to stem the seemingly infinite flow of tears, embarrassment tangling with his shame. "I don't know how you can look at me after all I've done," he said thickly.

Dean sighed. "Don't get me wrong, I was pissed at you for the longest time...but it's not like I've never done something stupid and gotten someone killed."

"But never a thousand in a single go."

"Well, no. But it's not something you can change. You wanna make things right, you just keep on saving people. It'll still hurt, and some people will always hate you for your past, but that doesn't mean you can't move on. You can get past this, Cas. I know you can."

The hunter's unending faith in Cas to do the right thing, even after the angel had proved him wrong and failed him so many times, made it all hurt worse. But somehow, at the same time, it provided a grain of comfort, and maybe a little bit of hope. "Thank you," Cas said, because it was something that needed saying, and because Dean was a better friend than he would ever deserve, and because now he had a pair of arms to fall into.

The comfort of another living being's warmth was a slight thing, still confusing to an angel who was so unaccustomed to it. But it was enough to stop the (foolish, childish) tears and ease the ache in his chest and allow him to regain his footing for another day.

AN: And here we are on the last day of grace! I am sorry the last chapter is so late and yet so rushed; life kind of happened to me today (the nerve of it!). It has been a real pleasure to write this, even if I will sorely regret posting it in, like, two months (in case you couldn't tell, this was a writing exercise I assigned myself: at least a thousand words per day for seven days. So it's not exactly quality-hell, most of it was unedited!-but there is a lot of it). I will mark this collection as complete, but I will probably revisit, especially if I get some suggestions. Thank you all so much for reading Rose's random ramblings! Live, love, and ship Destiel.

Carry on.