Regalun Petryph was a male Human, and he reigned as the King of Onderon. His rule occurred during the time of the renewed Galactic War, a conflict fought between the Galactic Republic and the Sith Empire.
Petryph's mother was Queen Lina of Onderon, making him her son. As he reached adulthood, his mother presented him with the Royal Hunting Lodge as a gift on the day before his initial hunting expedition.
After becoming king, Petryph observed that Onderon was a vital source of food for the Galactic Republic during a widespread food crisis. However, he believed that his government was not receiving adequate compensation for his planet's contributions. Consequently, he attempted to establish alternative trade agreements that bypassed Republic regulations and exploit Onderon's resources to enrich himself. These actions were strongly opposed by Senator Deja Nebet and his council of nobles, which forced him to retreat to his hunting lodge outside the capital of Iziz to avoid their scrutiny.
In the year 3627 BBY, Darth Savik from the Dark Council contacted Petryph. The Dark Lord flattered Petryph, convincing him that he was a powerful king and that Nebet and the nobles were conspiring to overthrow him. Unbeknownst to Petryph, Savik was merely using him to initiate an attack on Iziz as a distraction. This would allow Imperial forces to seize control of the orbital center and use the city's cannons against the Republic fleet that was refueling in orbit. Furthermore, she intended to manipulate Petryph to gain control of Onderon's resources for the Empire.
Despite the support of the Untamed, Petryph's attack on Iziz failed miserably, leading to a humiliating retreat. Back at his hunting lodge, Petryph received a projection of Savik through one of her remote droids, as she reported to Darth Malgus. After Malgus ordered her to withdraw her remaining forces, Petryph lamented that his enemies would imprison him for his failed coup. Savik then dispatched him with her droids, just as the Republic player, Jakarro, and C2-D4, stormed the throne room.
As the player, aided by the Untamed, tracked Savik to the Ancient Proving Grounds, she sent Petryph away in an Imperial shuttle equipped with a sensor jammer to prevent tracking. Petryph bid farewell to Onderon, promising to return and reclaim his throne. However, after the player defeated Savik, she freely provided the jammer's algorithm, leading to Petryph's capture before he could reach Imperial territory.
Upon the Imperial player's arrival at the Royal Hunting Lodge, Petryph is engaged in a conversation with Senator Nebet, who inquired about his return to the capital, but he dismissed her requests. Subsequently, the player intervenes in an assassination attempt by Gand assassins hired by Savik, before traveling to the Ancient Proving Grounds to kill to abduct Petryph's cousins, Anosek and Anoser, and frame both incidents on Nebet and the nobles. Petryph attempts to rally his bannermen to retake Iziz but received little support, so he suggested player recruit the Beast-Lord Akoru and his Untamed.
During the assault on Iziz, Petryph enters the throne room just as Nebet kills Akoru. He then accuses her of plotting against him, which she denies in confusion. The player then has the choice to assassinate Petryph and/or Nebet from a concealed position, earning dark side points but sacrificing the Empire's opportunity to control Onderon.
Alternatively, the player can reveal Petryph's Imperial connections. Although Petryph declared that neither she nor the Republic would rule Onderon, Nebet asserted that he was merely an Imperial pawn. The player can then instruct Petryph's bodyguards to arrest or execute Nebet. Afterwards, the player has the option of punching Petryph, much to his dismay.