I don't have any ideas to offer, but I do have some suggestions on how to find ideas. (I'm a specialist in creative brainstorming.) First of all, define your central idea clearly: What do you mean by "fighter"? And what do you mean by "intense adventure"? Then look at your genre: Are you looking at reality, or fantasy? Are all intense adventures about fighting? What would it look like for a fighter to go through an intense adventure where fighting was no help - say, an injured friend, and no way to get to a doctor? Lastly share some of your work with folks who like what you write, and ask them. To do great work, listen to your readers and fans.