Disclaimer: I do not own Ao no Exorcist/Blue Exorcist or anything recognizable. Blue Flames and Pink Smoke was originally written by WhitB and was officially adopted by me on August 17, 2017.

In a sequestered cave, somewhere in the forests of Japan, a miracle had just occurred. Some may say two miracles occurred, their names were Rin and Yukio.

Their mother, Yuri Egin, looked down at the tiny bundles of life with tears in her eyes. Despite the sad circumstances that the children were born into, the tears in here eyes were not tears of sadness. They were tears of joy.

Although this would likely be the last time she would see her children, it was by no means a sad thing. Though she would not live to see it, this would bring her one step closer to seeing her goal realized, unity of Assiah and Gehenna. These children - her children, were proof that humans and demons could coexist.

As she continued to gaze upon the two little infants with loving eyes, a tall, thin man emerged from the shadows.

"Greeting my dear Yuri, it seems as though my little brothers did a number on you." The man said, with a hearty chuckle.

Yuri glanced at the man and sighed. The time had already come.

"Hello Mephisto." She said quietly, her exhaustion was catching up with her.

Mephisto got down into one knee and looked her in the eyes, "You know why I'm here, don't you?" He asked in a serious voice.

She smiled weakly at him. She carefully presented on of the children to him, the one wrapped in blue flames.

"His name is Rin. Rin Okumura." She stated, "and this one here is Yukio Okumura."

To the unobservant eye, Rin looked like any other child. But if you looked closer, you could see that he wasn't quite normal. He had a tail, pointed ears, fangs, and faint blue flames encircling him.

Mephisto took the child into his arms and cradled him close to his chest. Rin clearly wasn't happy with being woken up and cried. Mephisto cooed at the now disturbed new-born, calming him. Mephisto then took Yukio from his mothers arms.

Yuri had no energy to protest, but she cursed Mephisto under her breath.

"Worry not, I'm only taking Rin. That was our deal after all. I'm just transferring the dormant powers in Yukio over to Rin so we have a full human, and a full demon." Mephisto explained. "As a full-blooded demon, Rin will be impossible to posses. He will also be able to come to Assiah without needing a host since he originated from here."

Mephisto chanted in a low voice, speaking in a language Yuri couldn't understand. He made small sits on the twins hands and rubbed them together. When he was finished, he gently placed Yukio back into the arms of his mother.

He took one last look at Yuri and said, "I will be taking my leave now, Shiro should be here at any second. To think I, the King of Time and Space, almost didn't make it here in time. Just because I can control time, that doesn't meant I can't lose track of it."

His poorly timed and awfully executed joke was meant to lighten the mood, but Mephisto wasn't aware that this wasn't the time or place to be making jokes.

With a poof of pink smoke, he disappeared moments before Shiro Fujimoto entered the cave to see Yuri, who was on the brink of death, holding onto only one child of demonic origins.