Complex sentence: Althena also decreed that there would be a champion called The Dragonmaster to lead Lunar's heroes; this person would be anyone who managed to make their way to the hidden lairs of the Four Dragons, and pass their harrowing trials.
Split into simpler sentences: Althena also decreed that there would be a champion called The Dragonmaster to lead Lunar's heroes. This person would be anyone who managed to make their way to the hidden lairs of the Four Dragons, and pass their harrowing trials.