the normal world awakened to a mythical world

A young adult called Rijin could been seen writing on his novel until a loud boom was heard all over the world.
The sky was split in two making a figure come out of it who said" welcome to the new era my name is cosmos and i control three galaxies under my belt from today you will undergo under a test where each of you will be selected randomly to get a power from a random character you know .

after you get it you will be transported to random universe from your worlds imagination of series ,where you will train your powers until you think you are ready to ascend to the tower of the gods "

someone asked the person in the sky"why are you doing this"

to which the figure in the sky said "of course so i can be entertained. hahahaha"