Villain of All Worlds! the Beginning Is the Big Devil

Obtained a system to travel through thousands of realms, but each time you travel through the identity, you can only choose the villain. No, I want to be the protagonist, change it for me quickly What! Give whatever the villain wants! Don't stop me, I'm determined to be the villain In this way, Xingchen's journey as a villain in all realms begins when he becomes the Demon King. Something seems wrong. Why does this brave man still need me to summon him?