I'm in Lilliput, Pretending to Be Ultraman

That day, the Demon King finally recalled the fear of being dominated by the giant and the humiliation of being imprisoned in a birdcage... Lu Xiao traveled to a different world, where the people were only the size of ants, but there were "giant beasts" everywhere, so he naturally came to the top of the food chain. He punched a giant the size of a toy and kicked a dragon the size of a sparrow. The devil even cried. Why is the fireball you unleashed as big as a building? Demon King: Don't be afraid, look at my 10-meter-tall undefeated demon body. Lu Xiao: Look at my 186-meter Fa Tian Xiang Di. Demon King: I'm going to break up with you. Let's see my ultimate magic that can blow up buildings - the end of darkness! Demon King: Wow, look at my invincible army composed of giant beasts and dragons. Lu Xiao: Look at my height of 186 meters, and then look at my shoes of size 4,500. The Demon King cried again: You are too bullying. If you have the ability, don't use the laws of heaven and earth. Are you great? Lu Xiao: Look at the fireball technique that is as big as my building.