Rengoth was an accountant in th Javervale who led a secret double life as the leader of the city's anti-republic resistance.
He was first encountered in Beating Heart, where he offered shelter and aid to the party as they were struggling to navigate the city to hunt the vampires living there. He showed a talent for illusion magic and an unwavering spirit, loyal to the cause of freedom for his fellow citizens. His situation at the end of the quest was left unknown as the party was forced to recall.
Months later, during Underworld: Rebellion, the party met with Rengoth and his band of rebels. The situation had changed. In absence of two out of their three major enemies, the Overseer and Ingo Astrodius, the rebels had planned a coup against Irma Astrodius. However, Ingo's timely return foiled their plan. It was at this time that the Vampires approached Rengoth, offering their strength to him. Many of the rebels embraced Vampirism willingly.
The party decided to ally with the rebels in their plan to assassinate the Astrodius twins. The coup failed spectacularly when Irma Astrodius wiped out almost all vampires with a single casting of Chain Lightning. Rengoth, now a Champion of Zuhra, the Vampire Queen, survived the spell but was immediately turned into a rat and captured by Ingo and his men. The party surrendered to the Republic, and were at the verge of disclosing the rebels' lair when Rengoth returned to normal and his back-up arrived.
While Rengoth dominated Ingo, the Progenitor Vampire along with Prissolu attacked the Republic soldiers. The party was once again forced to choose a side. The party sided with Republic felling the Progenitor while Irma freed Ingo, killed Prissolu and defeated Rengoth. After that, the party led the Astrodius to the rebels' lair where all vampires, including Rengoth, were permanently destroyed.