Parenting is harder than killing the Demon Lord

Once upon a time, in a land infested with strife and misery, the races banded together to kill a tyrant, a Demon Lord who wished not to rule, but to conquer and destroy, be it flesh and blood beings, or materialistic belongings, he wanted them all, encased in his crystal magic.
Many rose against him, even demons the same as he was, but none succeeded.
The many races faced defeat one after the other, against the mighty army of crystal soldiers, and the terrifying might of the Demon Lord himself.
That is, until a band of friends, a demon, an angel, a human, and a tree spirit, risking their lives managed to kill the Demon Lord, and with his fall, all his creations were undone as well.
The great war against the crystal army, and the many beings frozen in the crystal caskets were free, the war was over.
But at what cost?
The leader of the group, the human, and the healer, the tree spirit, died for this to happen.
These two were the links that held the group together, as the demon and angel always bickered.
But when the two died, the group died as well.
The demon, and the angel swore to never meet again, that is, until they were contacted by a common friend, and given the impossible task.
Their good friends, with whom they’ve defeated the Demon Lord, had a kid, and they wrote a will, saying that if anything happened to them, they would raise the kid.
And now, the two bought a house in the capital of the human empire, and tried to raise the kid together.
At first, it was okay.
The demon, Shdowal was nocturnal by nature, so the night cries, tantrums were handled by them.
During the day, the angel, Shuriel was non-stop with the baby.
And whenever the baby had a slight fever, or a slight ache due to growing teeth, Shuriel just healed him.
But time passed, and the baby grew into a fine young man, now at the age at which the humans usually enrolled into the Academy.
The place where they shall learn martials arts, and magic, one, the other or even both, while also focusing on the academics, learning history, economics and more.
And being someone raised by a demon, and an angel, both beings with long lifespans, both beings with extraordinary innate skills, and nonetheless, both of them being the ones who helped defeat the greatest Demon Lords of all time, the young man was quite extraordinary himself.
Aced the entrance exam, both theoretical and practical, has skills that put some younger lecturers to shame.
There was one itsy bitsy part that was worrying the two that raised him.
He was obsessed with them, with how they defeated the Demon Lord, and in consequence, he was quite obsessed and in love with the demons and angels as well.
And he never hid this obsession of his.
That’s why, today, Shdowal and Shuriel were invited to the Academy, for the kid did something…out of the line.
Besides beating two fellow classmates, he also beat a lecturer who tried to stop him.
And now, they had to talk with the Headmaster about this.
“Argh…We told you not to beat the other kids, didn’t we?
It’s obvious they are useless compared to you!”
Shdowal said.
The kid just smiled.
“But you said I should never lose a fight!”
He said.
The Headmaster just chuckled.
“Yes, Baldur, indeed we said that, but violence is not the first option we should use.”
Shuriel said.
“But you always smite Shdowal if the trash is not taken out.”
Baldur said.
Shuriel groaned.
“Baldur, please, go outside, I want to talk to your parents alone.”
The Headmaster said, smiling.
Baldur nodded, and left.
“Heroes, you raised a magnificent child, but…
His common sense is non-existent.”
The Headmaster said.
“Come on, he would survive even in the demon world, he’s alright.”
Shdowal said.
“Yes, he also loves helping others, and can’t stand injustice, he’s a kind soul.”
Shuriel nodded.
“Yes, but children are needed to be shown how to behave with others, how to behave in certain social circumstances, and how to handle interaction with others.”
The Headmaster said.
The demon and angel shook their head.
“I would rather face ten Demon Lords than to keep answering the unending questions of Baldur…”
Shdowal said.
“He sometimes jokes about helping the insects evolve a bit so they aren’t trampled upon on the dirt road…
I don’t think he’s joking…”
Shuriel giggled, but then sighed nonetheless.
“Parenting is harder than killing the Demon Lord was, right?”
The Headmaster chuckled.
They both nodded.
The Headmaster smiled.
“No worries, I already assigned him to be in the same class as several outstanding individuals.
They will be able to teach him a bit of common sense…hopefully.”
The Headmaster said.
With this, the meeting ended, and on their way home, Baldur managed to save a girl, who just happened to be a new joiner of the Academy as him…
Shdowal and Shuriel just sighed at this happening, knowing well whom he inherited this from…