Hogwarts: I'm Harry's older cousin

He became Harry's older cousin, a Muggle chosen by the original author.
As Xun Ge'er once said, "When Merlin closes a door, he opens a window."
After acquiring a strange mage system, Merlin opened a skylight above Dudley's head. Hmm, maybe Merlin ripped Dudley's roof off.
Dudley Dursley: "Let me explain, it's not what you think. I really am a spellcaster!"
Under the moonlight, Dudley twisted his waist into a strange pose, while background music played behind him: "Okay, I'm coming clean. I admit that wizards have their limits, so I'm not going to be a wizard anymore, Potter!"
"System, if you keep doing this, I'm going to learn the 72 Transformations and become a Super Saiyan."
This book is also known as "The God of Physics", "Anything But Magic", "Actually, I Can Do Magic Too", and "I'm Really Not Harry Merlin".
I already have three completed works of over one million words each, and one completed work of two million words each. It's guaranteed, so please feel free to add it to your collection.