At 15, he would likely bear a physical appearance reflecting his mixed heritage, with features that could be a blend of his Irish and Scottish ancestry. He might have a robust, muscular build, showing signs of developing the characteristic physical constitution of someone growing up in an environment where strength and endurance are valued, like the son of a motorcycle club president. He might have dark, slightly unkempt hair, possibly with longer strands falling over his forehead. His eyes could be intense and expressive, with a hint of mystery and determination in them. He'd likely sport a strong, defined jawline, adding to his appearance of determination and firmness. Regarding his attire, at 15, he'd probably adopt elements of the style prevalent in his environment, including leather jackets, club-logo T-shirts, and worn jeans. His attitude would likely reflect a mix of bravery, curiosity, and a dash of teenage rebellion, but also with a rooted respect for the traditions and values of the motorcycle club to which his family belongs.