DxD: King of Dragons

Have you ever heard of reincarnation? Well I'm in one of those situations.
"You have been granted a chance to reincarnate with three wishes, you have plenty of time so think about it"
"Okay, my first wish is to have dragons system, my second wish is to reincarnate in dxd world, my third wish is to receive my memories at the canon age, born to a rich parents but they died at a car accident leaving me an orphan with lots of money and change my appearance to this"
"Your wishes have been granted. Enjoy your new life."
In kuoh town
3rd pov
Here we can see a young man walking to the kuoh academy, suddenly he stops like he remembered something.
Toshiki Kai pov
"I see" I only muttered this as I keep walking, I then reached the classroom, goes to my seat and wait for the teacher to arrive.
Shortly after the teacher arrived and began to teach, Since I was smart and already know about this stuff, I pretend to pay attention but in reality I was thinking about my power.
After the class is over, I went to the toilet, and when I reached the male toilet, I open a dimensional portal, after I entered it the portal closed.
In inside the dragon dimension
When I opened my eyes I saw an endless lands, sky and sea, There I saw no living being except for me, this is a different dimension so the time flows slower, 'System' I said, {Yes? Host} answered the system, 'Can you show me your functions?' I asked, {Of course host} replied system, immediately a blue screen appeared.

[Stats]

[Skills]

[Inventory and Dragon dimension]

[Shop and gacha]

[Mission]

{Host, you have a starter pack, would you like to open it?} asked the system and I answered 'Yes'.

**[Starter pack opened]**

*[a stat up potion(random), minor regeneration and healing, three wyverns, two baby dragons, one teen dragon, 10000 system points, received]*

'System, open the shop' I said, {Ok, host}
[Shop]
Dragon scent remover
Description: a item that can remove all dragons scent for one day! [Prices: 1000 sp]
Dragon sizes manipulation
Description: ability to manipulate dragons sizes, only works on allies! [Prices: 9000 sp]
Barrier magic
Description: a magic ability to create, manipulate, barriers! [Prices: 15000]
'Since I can't buy barrier magic yet, I will buy the first twos, system buy me the first twos' I said to system, {Affirmative host}.