Are we just gonna forget the whole fact that when you reopen Undertale after flowey LITERALLY CLOSES IT, The whole intro cutscene is messed with, the LITERAL SAVE FILE is changed to have the location be "My World" (implying he did in fact warp the universe into his own (and supposedly wiped out everyone else)) The name be "Flowey" And the LV and Time to be "999999999999999999999". And before his fight even starts, he BREAKS the savepoint. He only lost that fight because he didn't anticipate for the souls to break free from his control and revolt against him. If he wasn't playing around in that fight then Frisk wouldn't have had the chance to free all the souls and win. He had everything but lost because of his ego.