Who is Liol from The Neutronium Alchemist Conflict and what is their importance?

Joshua's brother, Liol, has lived on Ayacucho dreaming of his father's return. When we first meet him, he is heartbroken, fearing his hopes will not come true. As the story progresses, however, Liol comes to appreciate Joshua's connection to and love of Lady Macbeth. As a result, he accepts that no-one but Joshua should be her captain.