Family Business and Saving the World

Disclaimer: This is my very first Supernatural fanfiction. I do not own Supernatural just the timeline.

Warning: This Story contains Desteil and supernatural gender-bending.

Prologue

It's been months since Earth had literally gone to Hell. For the Winchester family it's happened many times. This was the first time they had not been able to stop it. It all started when a demon named Lagina became the strongest demon who had ever walked Hell, Earth, and even Heaven. She successfully created a spell that allowed her to absorb powers from every supernatural being that she killed. She killed all the big demons in Hell and did another spell to give demons and angels the ability to live in their chosen vessel without ever needing another. They had their own bodies. However the cost of this was drastic. Their powers were halved and they were not able to use them as easily as before. This is how she was able to kill even Lucifer himself. After this year had passed and after taking over all of Hell she had taken over and destroyed Heaven.

In the year 2040 the Earth's downwards spiral had almost overtaken all. The only safe place was the bunker that the Winchester boys found so many years ago. There were only three that lived there now. Dean had lost his brother about 23 years ago but Castiel was able to comfort him and make sure he never lost himself. As usual he had blamed himself but at the same time there was another who also blamed herself. While trying to stop Lagina and her reign of terror the Winchester boys researched all they could to find a way to stop her. They found a spell that was supposed to cause a solution. However the solution was something they did not expect. Castiel had become a woman. He was still the same Cass but with changes that made him a full-fledged woman. After about a week Dean got drunk one night while Sam was out on a scouting run. Against his better judgement Dean's attraction to the female version of Cass caved in. When Sam came home he found Dean and Cass in bed together. As a little brother he laughed but let them sleep and said nothing more.

About a month later, Cass became pregnant. This was very new to him since angels had not been physically been able to become pregnant this easily before they were bound to their vessel. It was obviously a shock at first but they soon began to adjust to this new reality. They thought that maybe the spell did work. That the child Cass was carrying may be the one who was supposed to end all of this. Nine months later Cass was going into labor when the new queen of Hell came after them. Dean wanted to help fight her but Sam begged him to stay with Castiel because he needed his help. Soon their little girl Cassidy Winchester was born with a bright light similar to an angel's grace filled the room. Dean thought that despite all the horrible things that he had seen and been through over all the years of hunting this was the one thing that made his life feel content.
After Cassidy was safe in her crib and Castiel was resting and asleep Dean went out to check on Sam who was not answering his phone. When he got outside he saw everything bloody and body parts everywhere. He found Sam's body in shambles. He knew he wanted revenge for his brother's death but he also knew he had to protect that little girl no matter what. Sam made him promise to not bring him back and do anything rash if he was to die. A few days later Castiel was a man again. It seemed as though the spell only made him a woman until the child was born and he was healed. They gave Sam the Hunter's funeral and retreated into the bunker. Heaven was slowly becoming weaker and Castiel chose to stay with Dean and their daughter to raise her in the bunker.

For 20 years Cassidy was raised in the bunker with a very overprotective father teaching her the ways of hunting and fighting while her mother taught her everything else she needed to know. Dean still went hunting but only to the local cities and places near where they lived. Sometimes when Cassidy got older Castiel would come along for back up. She was visited constantly but the most trusted of Dean's fellow hunters and friends that he trusted. She was always spoiled on her birthday and Christmas. Even other angels who were still close to Castiel came to visit. When she was 21, Dean decided to bring Cassidy out for the first time. She was legal now and old enough to drink. She was able to go on her first hunt with her father and was a natural at it. All the training her father gave her paid off. They celebrated in a bar where she had her very first legal beer. (Obviously being Dean's daughter she had drank alcohol since she was a teenager.) The three of them hunted as a family and took on what was left of the world to protect all that they could. It took him a while but Dean even taught his daughter how to drive his baby. Three years the three had hunted until there was no one else left to save. The three retreated into the bunker with as much supplies as they could obtain.

For a few months things were quiet. They stowed away at the books looking for any possibility that they could think of for changing this world back to the way it was. One day Cass found something in the archives in Enocian that he had never seen previously. An option he never even thought of. He went to Dean immediately. He came into Cassidy's room where he smiled after finding his daughter clinging to her father who had fallen asleep with her. She must have had nightmares again.
"Dean," Cass said quietly shaking him.
Dean woke up suddenly looking up. "What…what's going on?"

"I need to speak to you about something I found. Come on." He whispered softly.
Dean nodded and followed into the living area. Cass explained everything he had read and Dean sat down silent. He couldn't. How could he send his daughter away like that? She was his everything after Sam died.
"Dean… it's the only option I could find. If we do this she could stop all of this before it even started. She's strong. She has the best parts of all of us. She'll be able to do this. We need to pack for her. Hunting gear, my angel sword, and old IDs from all those years ago. I know you have some left over that could be useful."
"Could you give me an exact date?"
Castiel frowned. "Sorry, but my grace is fading more and more every day because of Lagina. I won't be able to know where she will end up. In fact… it will take… all my energy and grace that's left to do this."
"Cass… no… there's gotta be another way…"

"There is no other option Dean. I'm willing to sacrifice myself if it means our world will be back to normal."

"R…right…" The two of them started packing a duffle bag with everything she would need when there was a loud bang on the door.

"Hurry!" Cass said as they rushed around.

"Mom? Dad? What's going on?" Cassidy asked with a yawn. The banging had woken her up and she was worried about what was happening.
"Listen Cassy, you and your mom are going into the dungeon and do a little spell alright? You'll be fine ok? Leave that bitch to me alright?" Dean said grabbing the bag and walking Cass and their daughter into the dungeon. Cassidy didn't know what was going on but she tried her best to hold back her tears. She was strong like her dad and wanted to prove it. When they got into the cell a voice rang from behind Dean.

"Oi! 'Ello squirrel, baby squirrel and angel bits." A malicious English voice sang from behind Dean.

"Cass… make sure she gets there safe. Cassy, I love you alright? Don't ever forget it." He said hugging his daughter and kissing her forehead. He closed the door and they could hear Lagina and her demons fighting her father.

Castiel quickly drew Enocian symbols all over.

"M…mommy…what…what's going on?"

"It's a spell. An ancient spell… It sends someone back in time. Unfortunately my energy and grace can only send you there. I cannot bring you back. When you get there keep a low profile. Only act when you need to. Keep listening to angel radio and if there is something wrong you need to fix it alright."

"Bu…mom…"

"Promise me alright? You need to save us." Cass said hugging his daughter tightly. "I love you. I never really understood humanity completely until you came along. I know you can save us."

"Mommy…" Cassidy said with tears in her eyes. She clinged to Castiel until he pushed her away. For the first time she had seen her mother cry. He had always been an angel but this was the first time he had ever really cried with her around. She took the duffle and clinged with tears in her eyes. Her mother started the spell and was halfway through when the door burst open.

Lagina was standing covered in blood. She stabbed Castiel with a knife while he was in midsentence.

"MOM!" Cassidy cried.

Lagina just laughed. "Your mummy's gonna die and then you are. You Winchesters ruined my Father. And now I'm going to ruin you."

Cassidy glared angrily and sent her flying to the wall. She grabbed her mom's hand and healed his wound as good as she could. It took longer for her to heal a wound but it was just enough or Cass to go on with the spell.

"Go on mom, I can keep you alive or this." She said with tears.

"I know. I love you." He said kissing her once more. He finally finished the spell as a bright light engulfed them all. Cassidy held onto her duffle bag as she felt herself being thrown through a portal. She was knocked unconscious from the loss of energy.