"Yes, it's almost complete, finally my theory will be proven to be fact!" a man yelled as he sprawls different markings on the floor while looking at a book. This man's name is, Junto Ryusuke, and his life in this world isn't very good. "OK, just one more dash and I should be able to cross out of this dimension," he drew the last stroke and a bright light flashed and he was knocked out.
When he came to, he found himself in a white room with a giant door behind him. He got up and looked at the door to see what it was. "You're a curious one, aren't you?" said a voice behind Junto. Junto turned around and saw a humanoid shape without any features whatsoever and it's voice was distorted making it hard to know whether it was male or female. "Who and what are you?" Junto asked. "Me? I am all, I am nothing, I mean nothing, but I mean everything. I am known by various names, god, the world, the universe, even the truth," the figure said in a gleeful voice. "So, why am I here? I just wanted to prove that other universes existed," Junto said defensively.
"You don't know the laws of equivalent exchange, do you? Basically, you will be able to visit other universes, but what are you going to give up?" the figure said in a mock questioning voice, "I got it! You'll have to defend every single universe from an all powerful evil! I think that's fair, but you will gain powers of your own as you fight, you will also gain the powers of every world you visit as well but they will be anchored to that world," the figure explained as it snaps it's fingers and a wide array of doors appear with different emblems on them.
"Now, what will you choose, Junto Ryusuke? Think carefully, you wouldn't want to run head first and kill yourself," The entity stated as it disappeared. (Hmmm, I have to think, all I can think of is the various symbols that might hint at a choice. Screw it, I'm going to pick THIS ONE!) he thought as he randomly chose a door.