2. Determination (without it, there's no chance of fulfilling their purpose).
3. A worthy opponent. (Sherlock Holmes is wonderful but Moriarty challenged him and Holmes needed that challenge. Your leads need those who will get in their way, try to thwart their plans etc. That's where the story comes alive).
4. A cause worth supporting (even if they are the only ones supporting it! Not quite the same as 1 above as a character can have a sense of purpose even without a cause. The great sidekicks in literature are often like this. Sam Gamgee in Lord of the Rings saw his cause as being supporting Frodo. It was Frodo who really had the sense of purpose and Sam didn't always understand Frodo's "intensity", Frodo had both the sense of purpose in that he had a job to do no matter what, which was at one and the same time also a cause worth supporting).
5. Courage. This comes into it somewhere in the story. It has to. The kind of courage can vary from the obvious courage in battle to the quieter kind where someone will keep going to support someone no matter what the hellish circumstances.
6. The ability to ask for help. Not every character has this. Recognising you need help and the best people to give it shows humility and pragmatism (as the character comes to terms with knowing they need help if they are going to fulfil their objective at all).
7. A mentor/adviser. This ties in with 6. A great character is going to need guidance to help them meet their goal and knows who to get that guidance from.
8. The ability to get on with most characters. This ties in with 6 and 7. Nobody is going to want to guide or assist a character who is arrogant or overbearing.
9. Planning. The character must work out how they're going to meet their commitments and then just get on with it.
10 . A cool head. Given the undoubtedly hellish situations, you are going to put your character through, they will still need a cool head to face down those challenges and press on towards their goal.