I cannot believe it. I have completely boxed myself in and have no choice other than to delete the file and start again. Clearly I picked the wrong units to take to the end. In Rebirth (3) you have to kill the dragon king, only problem is, the most points I can take from him is 10 out of the 100 he has. I did manage to get him to 70 in one turn, but he just got the points back on the next turn - it is a dead end. He will kill every character in one go and they won't take a single point.
I love this game, but I am not sure I can do this foe third time! Another 120+ hours? I am so disappointed I made a poor choice and there is no way to salvage it. If I do it again, I need to set aside a spare save file prior to the end chapters, so I can just go back to that .......... grrrrrrrrrr. Still a game I haven't finished.