How do you write a character with infinite strength without being boring?

So I’ve been thinking about writing a story lore for characters I’ve been coming up with. I would like to make a character with infinite power but they have to start off small initially and more they’re fighting or stressed out in battle, the stronger they become. So in a way their power work as a ramp instead of being able to be overpowered initially. To make more sense I would like a character that’s like Broly from DBZ but also a wildcard like Hulk.

How do I go about this?