I thought about that too. It could possibly be OoT Link. He was pained for not passing on his skills, which is true because OoT Link left without teaching anybody, and never returned. He mostly seems to mostly howl tunes from OoT and MM, which is oddly peculiar. Finally, he seems to select you, the holder of the Triforce of Courage, to teach his skills to. It makes a lot of sense, that he is a bloodline descendant of the Hero of Time(OoT Link). He would want to pass on his secrets onto to a descendant of his more than anyone else.
He also could be the father of TP Link which you never meet. TP Link's father might have been a great warrior, that would have passed his skills onto you, but died before he could. After seeing you being transformed into a wolf, he realized you were in great danger, and became aware that you needed his powers. He appeared to you and finally decided to give his skills to you. He then placed howling stones around hyrule knowing you could howl like a wolf to call him. Then he could pass the skills to you. He might have hid the fact that he was your father from you, because he didn't want you to know. I think it's possible.