I tried to make a new boss a higher stage, but I marked 5 entries in 1 at once. I did it, I defeated the boss, but instead of 5 times the reward I got only 1 rainbow reward. It even says that the reward for 1 entry is 2 rainbow items. I had did I get 10 not ????I also got only 1 energy point !!!

That reward you are talking about is a one time reward for beating that level of the boss. The energy point is also just 1 for first time completion of the boss(also caps at 10 btw). The rewards you got at the end, were for your passes…make sure to claim your one time completion reward off to the side in the main screen.