He couldn't help it. Not really. There was something that was coming. Something of Earth shattering proportions. God only knew what though. So he had to be content with his own duties, hopefully discovering what was to come.
To do so, he walked among mortal men. Not that they knew. No one had seen one of his kind in so long... It was just the same as always.
Men and women running around, living their lives, demons running as they sensed his presense, fearing for their lives. It made him somewhat sad. He recalled his days when he was a tamer. Gentle as they came and well known as a protector.
He didn't regret what he became, but he did miss the benevolent trapped under a malevolent name.
But even for a moment, he could ignore it as he went to the small park where children often played. Nothing made him happier than seeing children at play.
And nothing broke his heart more than what he saw instead.
The park was empty, sans one boy, about six or so, sitting at the base of a slide. Scrapes and bruises little red his body indicating a recent fight. His nose was a bit runny but no tears appeared on his cheeks. His eyes glared at his own scraped knuckles. The man gave a pitying sigh and walked over to the boy, unseen.
He crouched down and looked at the boy's eyes. Blue eyes shimmered with unshed tears. The man tutted and gently placed his hands on the boys. While he could not feel them, nor was the man gifted in healing, he could at least numb the child's pain. He ran his fingers gently on the boy's knuckles only to receive a surpring hiss, with the boy pulling his hands back.
The man's eyes widened seeing the irritation on his injuries.
No human would have such irritation. Well, no full human would.
"You're part demon," the man whispered in awe. It was not often half demon children were born, given that few demons would lay with humans and let the human live. This child... This child was a gift.
"Heavenly Father," the man spoke clearly, his head tilted back to the sky to face the heavens above, "Is this not one of your children? If he is, might I know his name? I fear that of all children, I know him not."
The man felt a warmth within in, then a cold fire. He let out a shocked gasp.
The demon -human son of Satan himself. He did know this boy. A boy humans had already damned.
"My Heavenly Father, is he... Is he doomed as the humans have spoken?"
He felt the warmth return to him. A small grin came to his lips.
"I see. Then may I... May I watch over him? I see not an angel's mark."
The warm feeling expanded rapidly. The man squealed in delight, his energy far more akin to a small child than a grown man. Despite not being able to touch the child, he wrapped his arms around the form. He placed a gentle kiss on the boy's temple. His dark curly hair intermixing with the boy's blue strands. The boy stiffened and turned his head slightly.
"Gah!" The boy yelped. Metatron dropped his arms as the boy jumped back, climbing slightly up the slide. Wide blue eyes stared back into his own brazen brown.
"Who are you?!" Rin yelled. The man turned his head slightly to see who was behind him, ready to defend the child.
"Hey! I'm talking to you!" Rin continued as The man realized there was no one behind him. A spark went through his heart as he fully realized the potential of having demonic blood. Or at least, the blood of a fallen angel.
"Can you see me Rin?"
"Who are you!? And how do you know my name?"
"Fear not little one. You are familiar with the Lord? Father Fujimoto told you stories right?"
"Right. Our Heavenly Father's flesh and blood on Earth. You saw how I appeared before you yes?"
"Yeah," Rin said a bit softer, "How'd you do that?"
"Well, I have been here-"
"Are you my guardian angel?!"
"Well, in a manner of speaking... Yes. I watch over all children."
"So you watch over Yukio too?"
The man thought for a moment. Yukio... The fully human child of Satan. He had Sandalphon watching him. Stronger than a mere angel, but not quite an archangel.
"My brother does actually. Sandalphon."
"Sandalphon. He's my twin brother."
"You're a twin? I thought Angels... You know..."
"Ah. Well you see, my brother and I," he began as he sat in the dirt next to the base of the slide as Rin slid to the base, "We are different from many angels. We, were born mortal men."
"So... Men can become Angels?"
"If one has a pure and loyal heart to our lord, then anything is possible."
"Cool! I want to be an angel when I get bigger!" Rin said excitedly.
"Oh Rin, one step at a time."
"Since you were surprised to see me, I'm going to guess, there are somethings you don't know."
"Duh. I'm six."
The man laughed at Rin's innocence.
"It's not funny Angel-San." The man quieted down his laughter into light chuckles.
"Please kid, call me Metatron."
Metatron, Archangel and protector of children. Especially those with high spiritual energy. He is an angel of truth, unity,education and ownership of ones own powers. He is one of two noted angels to have initially been human. The other, his twin brother Sandalphon.
A little bit of a spin on the whole, Angels in Blue Exorcist and interacting with Rin or Yukio. Or maybe not as there aren't a ton of stories like this. But this could still be fun. Rin having Metatron watching over him.