In Kaito's room
"While they're doing their own thing, in the meantime I'll find out what kind of ability I got" Kaito said with an excited smile as he took his notebook to write some stuff.
"Let's see... I don't feel as if my body were made of elements... that means it's not a logia type" Kaito commented as he cross out something in his notes.
"I also don't have the urge to suddenly turn into a creature like a zoan type user are so... that leaves with the paramecia type" Kaito commented again as he crosses another word in his notes.
'So its a paramecia type huh... but what kind though hmm... ' Kaito thought as he listed down multiple possibilities of abilities that he may have.
'It would be great if I had an encyclopedia for devil fruits, It'll make my work easier' Kaito complained as he couldn't help but slap the pencil down in frustration.
Poof~
Kaito momentarily paused as the pencil in his hand felt different, he looked down and was dumbfounded as the one in his hand were not a pencil but instead a... playing card.
"Huh?" Kaito was a bit confused as he thought for moment and couldn't help but connect it to the devil fruit that he ate.
'Is this what the ability I got from eating that devil fruit?' Kaito couldn't help but questioned himself.
Kaito experimented as he took another pencil and tried making it turn into a playing card again.
Poof~
He looked down at the other pencil as it turned into another playing card.
"So I can turn objects into... a playing card" Kaito couldn't help but muttered in a surpised tone.
Kaito experimented a few times if he could turn it into other stuff but alas it was futile as all of it still turned into a cards.
He sighed depessedly as he couldn't help but think what kind of luck he got to find such a useless devil fruit.
'NO' Kaito shouted in his heart as he could not accept his attitude.
"I shouldn't give up so easily, so what if it has a useless ability then I'll just make it not useless" Kaito stated to reassured himself.
'Maybe there are still more it can do with this ability' Kaito thoughts to himself as he took the playing card that were once a pencil.
This time he tried to turn the playing card into what it originally was.
Poof~
And it worked as the playing card turned back into a pencil.
"Oh this might be useful, this way when I travel, I could just turn my luggage into cards" Kaito commented in approval
'But is that all it can do' Kaito thought with a slight frown.
Before Kaito could do another experiment, a knocking sound was heard on his door.
Knock~ Knock~
The door opened and Ben came in with a serious look.
"Son what do you plan to do in the future?" Ben asked him in a serious tone.
"I-I don't know" Kaito replied as he really didn't have much of a goal.
"Then if you ever decide to someday leave this island and explore the world, come find me as I'll be training you" Ben stated as he exited the room.
'Explore the world huh... thats sound fun' Kaito smiled at the prospect of shocking the world with his greatest magic trick of all time.
...
12 years later
In the middle of a forest, a 18 years old teenager is standing out of breath while a muscular man is laying down on the floor.
"Hah~ hah~ after all these years I finally managed to beat you hah~ " The young man said after catching his breath.
"You're finally ready Kaito" the muscular man said with a proud look on his face.
"What if... I'm still not ready, I mean I still have a lot to learn dad" Kaito answered with a nervous tone.
"Trust in yourself Kaito... I know you're already ready for it" Ben stated to reassure him as he stands up and patted his shoulder.
"You're right I should have more fate in myself" Kaito said in a confident tone.
"Thats the spirit" Ben praised loudly as he patted him on his shoulder again.
It's been 12 years since I've made the decision to leave this island until I was ready enough.
When father knew of my decision, he started to train and teach me how to fight as well as taught me some survival skills.
I've also made some discoveries about my abilities as well since the last 12 years, I thought that the cards that I made were only for another form of storage but I was wrong.
I've found out that it could also be used as a weapon, as long as I used the right item, the cards could turn into a dangerous weapon.
This ability of mine of which I called [Dealer of Cards], not only could it turn into playing cards but depending on what kind of item I used, a part of its characteristics or qualities would remain.
Right now I have few arsenals (which are playing cards) stored in my sleeves, ready to be used at any moment.
...
Knives --> [Sharp Card]
Hard brick --> [Blunt Card]
Smoke bomb --> [Smoke Card]
Small explosive barrel --> [Small Explosive Card]
Handmade molotov --> [Fiery Card]
Poisoned darts --> [Poisoned Card]
...
I also have a "Card gun" that I requested from a friend of my father which by the way was a blacksmith.
It was quite amusing seeing the face of the blacksmith after asking him to build a gun that uses playing cards as a bullet.
Of course, I didn't forget to polished my magician skills, as It took me a while to regain some of my previous skills I had due to the new change of body.
I also practiced the art of disguise, although I wouldn't be able to train it to the point it matches the OP disguise skills of the real Kaito Kuroba but it should be passable enough.
...
At the Kuroba's household
"Ara~ have you finished your daily training already dear?" Elena asked as she's preparing dinner.
"Yes... oh that's right I was finally able to beat dad" Kaito said with a smirk.
When Elena heard that, she paused for a bit and looked at him with a sad look.
"So... It's finally time for you to leave... " Elena muttered with a sad tone.
Kaito just smiled bitterly as he walked towards the dinning table and sat down.
'This will be my last time having to eat my mother's cooking... I should cherish every moment of it' Kaito thought as he couldn't help but be sad at the thought of leaving them.
'There's no need to be sad... it was about to happen someday... the only thing I can do is be strong' Kaito said inwardly.
'I hope I'll be able to meet some interesting people' Kaito commented inwardly as he couldn't help but smile at the prospects of experiencing all kinds of adventures.