Being the old man that he is, Jack has a great deal of pity for someone else who can't die. He knows what it's like, and know that it isn't always the best place to be. But he knows how great it is, too. And while he wouldn't wish this upon anyone, he's glad that there's at least another person out there.

He's kind of like that cool uncle that takes you out to do things your parents don't like you doing. He really likes Claire, she's such a nice girl and in his opinion, she seems to get down on herself a lot when he thinks that no one should do that. Ever.

He kind of hopes that she'll adopt his philosophy of not caring what others think, not worrying so much, and just have fun, but he assumes that will come with age, too. (He has high hopes for her, and knows that she'll get past the tough spots of her ability.)

Me, I see him as more of a "mentor". Like Adam...except nice and not totally insane.