And that's how you make a healthbar video. (Sorry if this took 3 comments just to tell you how to make one)

Then, make a fight between the two. When they take damage, make some of their healthbar red. They are defeated when their healthbar is all red.

Do a healthbar video. They are easy to make. Just make two very short, very stretched rectangles (1 on the left for the good guy and 1 on the right for the bad guy)