Grizzled, mountain-dweller, hard-hewn. . . and, oh yes, NOT having raised him. I think his parents are both alive and did the raising. But at any rate, the great-uncle who shows up, because he's part of the wizards who are hiding the hero and others, is not raising any kids.
I think, in fact, that it may come up that he and his wife are estranged because they both did this work and as a consequence are sterile. Maybe not, it would put a thumb too heavily on one side of the scales.
But he comes and talks, hearty-like, to his great-nephew while he's in hiding.