If I Tame the Young Villain Again

I picked up a child who had collapsed in front of my house.
But for some reason, this child seemed oddly similar to the villain from a fantasy novel I had read in the past…
‘No, that can’t be.’
The villain in the story was an adult, and by now, he should be in the capital.
Trying to shake off the uneasy feeling, I decided to care for the child with all my heart.
Then, one night.
The child came to me, holding a pillow, saying he had a scary dream.
“As long as I see you, Ainra, I think I’ll feel better… so…”
“Should I help you fall asleep then?”
I offered out of pity, but the child’s response was strangely meaningful.
“…Ainra, you’re the one who said you’d help me sleep first.”
“So, it’s no use regretting it.”
I dismissed it at the time, thinking it was just a feeling.
But then—
“Did you sleep well, Ainra?”
When I woke up, the child was gone.
And in his place… was a fully grown man?!