Master Of Magic Cards

I traveled back to a parallel world similar to the twentieth Century. I was just an ordinary civilian there.
But one day, I found a secret in the castle I was employed, a secret that could help me become a master.
And at this time, the nobleman and his son died unexpectedly, and I replaced his son's identity.
So I accepted his secret and opened the book of magic cards.
After that, legends about me began to spread on the continent.
Someone called me Master of Magic Cards Blessed by God.
Someone also called me the Eye of the Devil.
Someone even called me the Creator of the New Century.