I'm a Young God, Won't You Raise Me?

A former pro gamer who retired due to injury.
After retiring, I spent my days just playing games…
Then the game I used to play became reality.
But I am not a Player.
[You are the System of planet 'Earth'.]
It wants me to register people as characters, but I have no idea what that means.
For now, let’s just clear it first.
After all, I know everything about this game.