The Ancient is mentioned in the in-game tutorials. Dim, The Solar Mole, acts as the mentor for new players and explains to them of the unfortunate tale in which The Ancient placed a curse over the people of Fates Forever - transforming them all into different species of animals.
Through the creation of a tournament held on the Vale of Redemption, The Ancient has given the people a chance to remove the curse. Those who choose to fight as Contestants and becoming victorious in battle will also win their freedom in return.
Not much else is known about The Ancient or for what reason the curse was made for.