The morning sunlight crept through the curtains, warm and gentle, settling over the two sleeping figures on the bed. Keith stirred first. His eyelashes fluttered, and his sapphire-blue eyes slowly opened to the quiet room.
Then—
A flood of memories surged through him.
His past life.
His death.
His reincarnation.
And the realization that he was now in the world of Harry Potter.
Keith gasped softly, gripping the sheets as the memories slammed into place. Everything from yesterday suddenly made sense — the letter, the dizziness, the collapse.
"So… I really was reborn," he whispered to himself.
And with that thought—
A chime echoed inside his mind.
[System initializing…]
Keith froze.
[Welcome, Host.]
He felt his heart skip. A system? Here?
"What kind of system are you?" he asked silently.
[Answer: This system is a Sign-In System.
Host may sign in once per day or at special locations.
Rewards vary in rarity and power.]
Keith exhaled slowly, excitement bubbling in his chest.
A sign-in system… in the Harry Potter world? This was beyond overpowered.
His eyes drifted to the side.
Luna was still asleep, curled beside him, her fingers wrapped tightly around his hand as though afraid he would disappear if she let go.
Soft, peaceful, vulnerable.
A side of Luna Runcandel no one except Keith would ever witness.
Smiling gently, he squeezed her hand.
"System," he thought, "sign in."
[Affirmative.]
[System Notification: First Sign-In Complete.]
[Congratulations, Host.]
[Rewards Granted:]
— Unique Skill: Great Sage
— Unique Skill: Predator
Keith's jaw dropped.
He nearly jumped out of the bed.
Great Sage? Predator?
Those were Rimuru Tempest's legendary abilities—absurdly strong even in Tensura's world. And now they belonged to him?
His heart raced.
If they evolved into Raphael and Gluttony… then even the strongest Hogwarts magic wouldn't stand a chance.
He swallowed and whispered mentally, "Great Sage?"
[Hello, Master.]
A clear, emotionless voice echoed elegantly in his mind.
Keith laughed under his breath in disbelief.
He had Rimuru's best cheat.
Before he could test anything further, Luna stirred.
Her amethyst eyes blinked open, still hazy with sleep. The moment she realized Keith was awake—
Her arms shot around him, and she buried her face in his chest.
"Keith… Keith…!" Her voice trembled, tears gathering once more. "You scared me. You scared me so much…"
Keith's expression softened.
He wrapped his arms around her small frame and held her tightly, stroking her silver hair slowly.
"Sorry, Luna," he whispered. "I'm here. I'm okay."
She clung to him, trembling. Last night had shaken her far more than she showed. Seeing him unconscious—after losing their parents—had almost broken her.
When her tears finally slowed, Keith gently wiped her cheeks.
"Luna," he said softly, "there's something I need to tell you."
Her eyes widened slightly. "What is it?"
He took her hand, steady and warm.
"I… recovered my memories. From my past life."
Luna froze.
Shock flickered in her amethyst eyes, quickly followed by surprise and confusion.
"You… what?" she breathed.
"I lived another life before this," Keith explained calmly. "I died… and was reborn here. This world—this is the Harry Potter world I knew from my previous life. But I don't know how identical it is to the story."
Luna stared at him for a long moment.
But instead of fear or disbelief—
Her expression softened.
Keith squeezed her hand gently.
"No matter what world this is… I'll protect you," he said firmly. "I won't let anything harm you. I promise."
Luna felt something warm burst in her chest.
The Keith she knew had always been sweet and cute.
But this Keith—
This Keith who spoke with determination and warmth—
Was someone she couldn't look away from.
Her heart pounded.
Slowly, she leaned forward and kissed his forehead.
"Keith…" she whispered. "Thank you. For trusting me."
He smiled.
"And there's more. I got something… a helper."
"Helper?" Luna blinked.
"A system," Keith explained. "A sign-in system. It lets me sign in every day and get rewards. Today I got two skills: Great Sage and Predator."
Luna's eyes widened further.
"W-What? Those are… those sound powerful."
Keith nodded. "They're extremely powerful. Even world-breaking."
Luna stared at him, stunned.
Her younger brother—her fiancé—was becoming something terrifyingly strong.
But instead of fear, pride surged in her chest.
She smiled softly and hugged him again.
"Keith… no matter how strong you become, I'll stay by your side."
And Keith hugged her back, knowing that the path ahead—
magic, swords, systems, and destiny—
would be something they would face together.