Hehe Second form has 120000 hp
If you don't want to train,let all your aeons exceed overdrive limit.
4*9999+40000+20000= almost 100000
All you have to do is make 20000 dam to The final aeon then launch all your aeons! Easy,ya????
But to make the last never-lose-battle with your aeons quicker,you should let Yuna learn strong magic(Holy best choice),I pretty sure that you can't hit the aeons with physical attacks.