Who is Calum MacInnes from Stories: All-New Tales and what is their importance?

Calum MacInnes was a reaver in his youth and is comfortable traveling light. When asked to act as a guide to the cave on the Misty Isle, he takes only a rope and a dirk. He is married and has one son. He is a tall man, with a loping stride and eyes of gray. He has a face that is long and somehow wolfish in appearance and his hair is streaked with the gray of age. In good health, he is engaged as a guide to lead a wee man to the cave on the Misty Isle.