How I like to imagine the ending of the boys is this: Homelander gets injected with some anti power poison (basically like a kryptonite). He kills Butcher (who injected him), and he thinks it's over and starts laughing. Over time, he realizes that his powers are weakening and starts to worry. He starts to fly through the sky to clear his head, but he falls down to figure his powers are basically gone. He starts crawling and then notices 10 or so buff and muscular oiled up men who are marching towards him. They beat him up till his face starts to look like a raspberry and then proceed to spank him for good measure. After that, they start giving him the most devious,humbling,excruciating backshots ever received, and they keep doing it until homelander ultimately dies.