For example, the end-of-season fights in Dragon Ball Z, the fights between the Eva and the Angels in Neon Genesis Evangelion. I've noticed it in far more things but these are the most recent in my memory.
When a fight is occurring, the more damage which is done to something, even if it is mechanical, the more powerful it (sometimes) becomes. That doesn't make any sense to me.
I would prefer an explanation which relates to Japanese culture, if such a thing exists (for example, the reason why anime has a lot of characters / machines with weapons attached to their arms is because the Japanese are of the view that weapons are an extension of the body, not something to be picked up and thrown away like a pistol in an American action movie - that kind of thing). However, any insight at all would be great!