Disclaimer: I don't own Buffy or Supernatural.
AN: I've never seen an episode with Castiel but I've read enough fic with him that I feel I can at least attempt to write him. I just feel the need to warn you that he's probably very OOC but then, maybe not, he hasn't had the influence of a human host or Dean yet.
"Castiel's Mind Voice"
This takes place immediately after Buffy jumps.
Dawn wandered dazedly down the tilting steps, which only seemed to tilt more as the world spun around her. Buffy had jumped. Buffy was ... It should have been Dawn. It had been her blood that had opened the portal - her blood was what was needed to close it. It wouldn't have mattered anyway. She wasn't real. She was just memories and Buffy had ... had jumped for something that shouldn't have existed.
Dawn made it to the bottom of the tower, feeling her knees give out as she saw Buffy. A sob caught in her throat. It wasn't real. This couldn't be real.
The voice made Dawn jump, her eyes flicking around. She found no one but the Scoobies huddled together in misery.
Great, she was going nuts ... but given what had just happened she guessed it was expected.
A gentle laugh eased over her like a balm for her soul. It still hurt but the pain was dulled. She felt she could at least make it home before her world crumbled. "You are not crazy, Dawn Summers. I would come in person but the Hellmouth is not safe for our kind."
*Your kind?* A demon? This was just what she needed right now ... but it didn't feel like a demon.
"Not a demon, child. I am something much different. I come baring news."
*What are you and why are you in my head?* Dawn could hear the indignant whine in her voice and forced herself not to blush.
"We have many names but the one most familiar to humanity is Angel."
*An ANGEL??* Why was there an angel in her head? A kernel of doubt wiggled through her mind. What if it was just a demon - a telepathic demon? It could happen. This was the Hellmouth after all.
Dawn felt more than heard the sigh. It was the type of sigh her mother, she ignored the sharp stab of pain at the thought, used to give when she was being particularly stubborn.
"An Angel" He confirmed. "As I said, I come baring news."
A hint of resentment wormed its way through Dawn. Her sister had just ... just died and her mother before that and an Angel wanted to talk to her NOW? Why couldn't they have warned her before Buffy or even her Mom? Why did they choose now of all times?
Dawn felt the sympathy radiate from the voice. "Destiny is a hard thing to please, especially for those left behind. It was your sister's destiny to save you. Just as she is now destined for something greater. This, though, has left you without a protector."
Buffy was destined to die for her? *What do mean destined for something greater? Buffy's dead.* It seemed to get easier to think as the voice dulled her emotions. Probably so she could think rationally.
"We don't have much time before my presence, even as small as I have made it, draws attention. Your sister is here, with us. Her destiny is unfulfilled so she will stay with us until the time comes. She misses you already." The last statement was added as an afterthought. As if he couldn't understand how Buffy could miss her already. Almost as if, maybe he couldn't understand the emotion at all.
*She's okay?* Dawn felt her hopes soar. If Buffy's destiny were unfulfilled, she'd be back.
"Yes. She is perfectly fine."
Dawn's eyes were drawn to the body at the bottom of the tower. The body that the Scoobies were all gathered around. It seemed they'd forgotten about her for now.
"But this leaves you without protection."
*What do you mean? I thought I was done. Giles said it was a one-time use. Even Glory said it had to be now - with such and such in the right alignment.*
"For this ritual, yes but there are other uses for one such as you. Glorificus could only use you to open the way to her world inow/i, at this time but there are infinite realities and worlds that need a Key. Infinite possibilities and rituals with their own alignments."
Horror surged through Dawn. She thought she was done but she knew enough about rituals and planetary alignments to know just how many different ways she could now be used. He was right; there were infinite possibilities. If she could still be used, she was in danger every minute of every day. Not only was she in danger, the world was in danger from her.
"Yes, I see you grasp the direness of the situation. Your protector is gone and while I have been tasked to watch over you there isn't much I can do. I have no host and even if I did, I would not be able to step into range of the Hellmouth. While that, in itself, will protect you from a variety of demons and evil it will not protect you for long."
*What do we do?* Dawn resolved herself to doing what was needed. She may have been young but she understood the situation ... probably better than any of the gang would but for Anya and Giles. They'd fight her on it, wanting to keep the last piece of Buffy with them but either they'd resent her for it when the demons started coming for her or they would die for her just as Buffy had and there would be no coming back for them.
The voice seemed to hesitate, to contemplate the situation before he answered reluctantly. "I will need a human host. I am ... hesitant as once I take a host contact with you will be limited. While my powers will be nothing short of awe-inspiring to humans they will be constricted, bound to a host."
Dawn thought for a moment. *How long to put whatever plan you have into motion? How long would I be on my own?*
"A few weeks given the stubbornness of those I have in mind."
Dawn glanced back at the Scoobies. Seeing they were still debating what to do with Buffy, she wondered if the Angel had done something to them. *I think we can manage for a few weeks. It will take that long for word to get out about what happened here and for them to come for me. They can probably hold off the first wave. The more powerful will want time to prepare.* Dawn thought nothing of how her thought processes had sped up. She thought nothing of how mature she was handling this situation when not even yesterday she would have whined and screamed. Her mind didn't connect this with the amount of power that had to have been used to talk to her or how long that power had been wrapped around her so soon after her own power had cracked the world open.
"Very well. I will begin the search for a host."
Dawn felt the presence begin to withdrawal. *Wait! I don't even know your name.*
His smile came through as he answered. "I am Castiel."
Buffy is being saved for that big 'End-of-the-World' Battle. She's become some kind of Warrior Angel. When Hell opens and the demons pore forth, Buffy will be the one leading the Good Side's charge.
I'm pretty sure I'm done writing this but I'll leave this open to other authors just in case it sparks something for you. Here are a few questions that should be answered at some point and a bit for you to think on.
A simple explanation as for why I made Dawn more mature ... There would be a huge chance of Dean shooting her if she was the same whiny brat from the show. I think even Sam would be tempted after a while. That's not something I'd want.
Castiel will take his human host and contact with Dawn will be sparse. He'll try to convince the boys (could be earlier than he appeared on the show) to take in and protect Dawn. There's also the resurrection to think about. Will it happen? If it does ... What kind of screw-ups will happen? What about Buffy herself? As stated, she's a Warrior Angel - How will that come through to her human form? Will she stick around SunnyD or will she search out Dawn? To drag her back or to help protect her?