all right, settle down a bit.
it is in fact the final boss again, but it's like the elite four and champ for pokemon. You can redo them, gain more and more EXP, blah blah blah. It's quite simple really. You need a healthy team from the incubator then just kill him again, wait for credits to finish, and.....voila. you save and more exp by like 300!
I feel so rejected.....from what you said. :(