No one ever thought that someone would be able to take down Superman. Kal-El didn't even know that he had a weakness. That was until he met a villain who seemed to know too much about him and his weaknesses. He had barely survived the battle, he had never expected that one person would be able to bring him so close to death. The only thing that kept him up right and fighting was the fact that he was the last strong hold between this villain and the Earth he had come to love so deeply.
Once the battle ended he laid in the road, a crater that his body had created, surrounded him. He could barely take a breath, a green rock sticking out of his side. He couldn't even lift his arm to pull it out. His vision went in and out, he got flashes of Batman swinging in, flying towards the Justice League Hall, going up to the Watch Tower, and finally ending up on an operating table. The last thing he remembered was watching the prettiest doctor he had ever seen walk in before he lost consciousness.
When Batman showed up at your clinic to recruit you for the Justice League you thought it was a joke. But, Batman never jokes. He offered a tremendous salary and instantly the Wayne Company was backing your clinic, giving you enough funds for state of the art tech and enough staff and salary to pay them so you would never have to charge a single patient. You couldn't say no, what was the worst that could happen? That was until you were in space on a floating satellite with an Alien Hero stabbed with Kryptonite was laying nearly dead on your operating table. "Pretty." was the last word he said before he passed out and all the nurses looked to you for the next move.