I found this fanart and had to use it even though Estarossa isn't in the oneshot. Anyways, enjoy!
You were walking with Zeldris and Meliodas when you saw a traveling caravan. You wanted to get something from it, but couldn't when Zeldris grabbed your collar and held you still as you tried to wander away. You pouted and waited for him to get occupied until you slipped away to see the caravan after telling Meliodas where you were going while he was also busy. When you got there, a bag was thrown over your head, and you were thrown into the back of the caravan.
Zeldris looked around for your adorable face a few minutes later and panicked when he didn't see you. He then remembered that you were seeing the caravan and took off after getting Meliodas's attention and telling him. The demon nodded and got back to his conversation with the shopkeeper in the town they were staying in.
You were taken out of the bag and thrown into a cage as you got paraded around the place you were in. "Young demon, only fifteen gold coins!" the man who kidnapped you yelled. You heard a man say that he would take you as tears threatened to fall down your cheeks. However, the man didn't pay the price of fifteen gold coins. Instead, he threw off his hood and socked the man who was selling you in the stomach. You watched as he fell over in pain while you got whipped by the other people and smiled. It was Zeldris who had been wearing the hood, and he did not look happy. He saw you fall over and black out as the other people began to fight while he got rid of the bars. He picked up your limp body and carried you back with him as he flew using his darkness to get away.
When you woke up, you felt a hand grasping yours and turned to see Meliodas. He was asleep, and looked very tired as you hugged him. His eyes shot open as a single tear slipped down his face. You looked at your brother, a sheepish look on your face as you spoke. "Sorry for not listening to you and Zel." you said, tears starting to fall down your face as you buried your face into his hair. He smiled, hugging you close to him. To Meliodas and Zeldris, you were like a soft cushion that they could lean on when they were sad, so when you got sad, they hated it. You saw Zeldris walk in and smiled, reaching out your arms to him. He ran to you, tears rolling down his face as he hugged you tightly. "Please don't do that again, we could have lost you." you were hurting all over. There were cuts and bruises that you couldn't heal, and needed to be bandaged by the two. After you were fixed up, the two of them, not including Meliodas, made you dinner in bed. Afterwards, you fell asleep with them, happy to be safe.