【How-to】Who is the guy with the hat in bleach

The Soul King (霊王, Reiō) is the supposed ruler of Soul Society who resides in the Soul King Palace and is protected by the Royal Guard. In reality, he is a god that has been sealed, and his existence is tied to that of Soul Society, the Human World, and even Hueco Mundo. The Soul King is the father of Yhwach.