There are conflicting sources regarding Goultard's year of birth. According to his birth certificate in DOFUS: Goultard Bazar, he was born on "the fifty-third leap year of the Bow Meow, the third day of the seventh moon", but his page on Krosmoz.com mentions his involvement (as an adult) in the Shushu invasion of the year 24. A timeline found in Ankama's studios gives -1111 as his year of birth. As the DOFUS Manga are not considered canon, this latter date appears to be more plausible.
He is Percedal's trainer. He helped Percidal take down the demon King Rushu and banished him and Rushu to the Shushu realm, where he killed him and became king of the demon realm. During the Season 2 three part special, he gifted Percidal with the power of the god of war; Iop. After the fight with Ogrest, Percidal gave his powers back to Goultard, saying he didn't have much fun being a god.
Once Iop gave him his powers, he had the form of Dark Vlad. Dark Vlad comes very rarely and comes when defeated in a battle. Same way to turn back. He destroyed a city which used to be beautiful which is also the desert Percedal finds him in later.