Lolirock: I’m Mephisto and I have a supernatural smartphone

Synopsis: After answering strange questions online, Damien died due to an unknown explosion in his apartment. Luckily for him, he ended up in the story he had mentioned to the stranger online, with his only power being a smartphone capable of communicating with anyone in fiction who has a phone.

Author's note: I'm a capricious author, so this was born out of a whim and could disappear just as easily.

Bonus info: Yes, this is a harem (I see you coming, lol).

Protagonist's power: It's just a smartphone capable of calling and writing to anyone, but the protagonist must buy the individual's number with points in the app store. The internet works thanks to his magic or endurance, and internet from other dimensions is expensive.

Note: The protagonist isn't really a genius (he's slightly above average). The phone is indestructible and will always find its way back to the protagonist if lost. If the person being contacted doesn't have internet (or network), it doesn't prevent them from being contacted by the protagonist if they have a phone.

[any works of fiction mentioned or appearing in this fanfic are not mine like lolirock, I'm just a fan writing fanfic for fun]