What makes a great fighter?

Intangibles that are a part of his personality, not physical skills that are taught and learned in the gym. Specifically I would say willpower and improvision. A fighter with will never quits and can keep fightin when shit ain't goin his way. He can be hurt, cut, tired, knocked down, or whatever and still have it in him to keep fightin harder than the other guy. And a truly great fighter is a complete fighter that can make adjustments. He's a soldier that doesn't have a bullet with his name on it. No matter what his opponent's style is he can find a way to win. If plan A ain't workin he has B-Z ready to go. If his opponent changes his strategy midfight he can change too and stay a step ahead.