My Smartphone Got Turned Into a Spellbook!?

When I woke up, I wasn't in my room.
The ceiling was made of stone, not plaster. The air smelled like smoke and wildflowers - and there was a giant crystal glowing on the wall.
The last thing I remembered was scrolling through my phone during a thunderstorm, laughing at some meme about "isekai deaths."
Then-
BOOM.
Lightning struck outside my window, my phone vibrated like crazy, and everything went black.
Now, here I am - lying on the floor of what looks like a medieval castle.
I reached for my pocket, praying my phone had survived.
It did... sort of.
The screen flickered to life, but instead of my usual apps, there was only one icon:
📜 "SPELLBOOK.exe"
"What the-?"
I tapped it, and a holographic page opened mid-air, glowing blue.
Words began to write themselves:
"Welcome, User. Magic Calibration in Progress."
"Detected Energy Source: Mana."
"Battery Power = Life Force. Use Wisely."
I stared. My phone had become a grimoire.
A voice followed - calm, digital, and oddly smug.
"Congratulations, Riku Tanaka. You've been selected as the new Arcane Operator of the Ether Realm."
"Huh!? Wait-where's the Wi-Fi!?"
"Wi-Fi? You mean 'Wisdom-Fiber Interlink'? Activating mana connection..."
And then, out of nowhere - a bright blue portal opened in front of me.
A group of armored knights appeared, swords drawn, shouting in a language I didn't recognize.
I raised my phone instinctively - and the word "Fireball" appeared on the screen.
"Voice command accepted."
A burst of flame shot out, blasting the floor in front of me.
The knights froze.
I froze.
And that's when it hit me:
I just cast a spell using my phone.
Somewhere in the distance, a voice echoed - soft, feminine, and ancient.
"The Operator has awakened. The balance will shift once more..."
And just like that, my normal life ended -
and my adventure in a magical world began.