Complex sentence: Also known as Lord Mathias or Mathias-sama, he is the Leader of the religious Organisation which supports the Orb Hunters, more commonly known as the Purifying Ability Compatibles.
Split into simpler sentences: Also known as Lord Mathias or Mathias-sama, he is the Leader of the religious Organisation which supports the Orb Hunters. The Orb Hunters are more commonly known as the Purifying Ability Compatibles.