Vil Kothos was a Human male Dark Jedi who was a high-ranking cult member of the Disciples of Ragnos.
Along with his twin brother, Dasariah, he was known as one of the "Kothos Twins" or "Reborn Twins." The two twins became legendary symbols for the cult, and were powerful opponents for any Jedi. Unlike most of the New Reborn members of Tavion Axmis's cult, Vil did not use lightsabers, but relied instead on his tremendous abilities in the dark side of the Force and Force-enhanced acrobatics.
Both of the twins were considered masters of the dark side of the Force, and their dark side abilities probably even surpassed those of Tavion, who concentrated more on lightsaber combat.
Vil Kothos wore an orange battle suit and had an almost inhumanly deep voice that was enough to scare the wits out of many sentient beings.
The twins accompanied Tavion Axmis to the Massassi Temple on Yavin 4 where she syphoned the Force energy from the temple with the Scepter of Ragnos. They later assisted Rosh Penin when he dueled Jaden Korr in the Bast Castle on Vjun, empowering Penin through the Force. Korr realized that if he were to have any chance of beating Penin, he would have to defeat the twins first, while warding off Penin's attacks. The twins used all their power to keep Korr from harming Rosh.
While powerful in the Force, the twins were eventually both slain by Korr who afterward defeated Penin. Despite their acrobatic skills and Force mastery, the dark side alone was not powerful enough to beat Jaden Korr and the twins ended up dead on the cold floor of Bast Castle, being consumed by the dark side of the Force.