Champion of Evil
The Yaun-ti invaded Ubel (insert time here), your clan was on the brink of victory when a young human came to Ubel. The human wore the symbols of Hieroneous and valiantly fought off many of your clan, strikes against Ubel. He had systematically discovered which of the town people and political figures the Yaun-ti had planted into the city and had them all executed. It had seemed like the battle was lost but the clan elder refused to lose at something he worked so hard to get. On the brink of defeat, a man wearing full plate mail wanders into the Ilan forest looking for the Yaun-Ti high priest. His armor beared holy symbols of Heironeous, the Yaun-ti attacked him trying to slay him but he was much stronger than any of them, and possessed some evil power. This made the high priest curious of what he wanted and allowed them to meet. The man offered the high priest an offer he could not refuse.
The man revealed his name as Schurke Canalla. He said he would help make the Yaun-ti a force to be reckoned with if they would do a couple things for him. They needed to stop their assault on Ubel, and allow him free access to their ruined city in Ilan. They were also to capture and turn any human captured in the Ilan forest into brrodlings that Schurke could use in Ubel.
The High Priest Korge Mataas, agreed to the stipulations. Schurke then offered to make some of the Yaun-ti pureblood into more powerful versions of themselves. He would turn them into vampires. You were among the pureblood that were turned. Schurke did not reveal what had turned any of you but all of you who volunteered were bitten by something.
All changed by the transformation were called the elite, and referred to as the Mort Viboras. The Mort Viboras work in secret infiltrating cities all over Nemir turning anyone they can into vampires to join the army, and become political figures in the city.
You four have always stayed close to Ilan, running missions out of the forest to local cities and setting up ambushed on the humanoid caravans. You have been creating spawns and sending them to Ubel where they are tested by Schurke to see if they are worthy to be in the army.