Complex sentence: However, the ruler of the fire nation Fire Lord, Ozai, was the second eldest son, but he managed to scheme his way to the throne and usurp his older brother, Iroh, of his birthright.
Split into simpler sentences: However, the ruler of the fire nation Fire Lord, Ozai, was the second eldest son. But, he managed to scheme his way to the throne and usurp his older brother, Iroh, of his birthright.