Jak, I understand your eagerness to want to do something great. But the thing is, these things can't be forced. Some of the greatest things that I've done, and seen done, happened in threads where there was no planning. No one set out to do something great. These moments simply happen. And they happen when we try to tell a story.
A New Hope wouldn't have been nearly as interesting if Luke started off the way he ended up in Episode VI. If the hero is already the greatest around, and can do whatever he wants or get whatever he wants, what's the point of caring? The greatest moments that come for us as writers and roleplayers come from those moments that fit like in the movies or from great books.
Right now, I don't know anything about Jak. All I know is what I can read in his bio. I know he collects weapons, and that his father was killed when he was younger. But I want more than that. I want to see who Jak is when no one's looking. I want to see why he collects weapons and old technology. Why does he do the things that he does? It's when you stop trying to force greatness that greatness comes to you.
Start by telling a simple story. Just a boy with no idea of where to go or what to do, with only a dream and a desire to change the galaxy. Show his struggles. Show him stumble. Show him fail. When you do those things, when you build your character up to be more than just a face and power, that's when you'll find that there are things that Jak can do that even you didn't know he could.