[@Dark Cloud]It depends on the individual. Only the Old Gods were powerful enough to create worlds, but a New God is easily enough to render one lifeless. Attaining a Key of Creation grants you a sliver of cosmic power. This on its own makes you a shit-hot demigod. Think like, Super Saiyan Goku. It also grants you the ability to travel through the Multiverse and do other divine nonsense, which opens up new and exciting forms of power to you. So with training/study/what have you, you can easily become much, much more powerful than that.