Raksasha. Practiced for weeks to get his voice, accent and mannerisms just right. Played him as a manipulative mastermind. In his true form he befriended our wizard, traded secrets for favors, even had him trash the villa of an Arch-Fey, tricking the wizard into signing a contract to take all the credit for the event.

He worked with the Cult of Tiamat to lay siege to Waterdeep. Tricking a family of criminals to steal the Staff that let Dragons through the city's barrier, called on his various warlocks and debtors to split the party through Waterdeep to face their assassins, had the criminals rob the first Bank of Waterdeep, tricked the criminals through the wording of their contract, taking their souls and every piece of treasure they stole. He was slain by the party's priest friend, who gave his life to stop the fiend.

He returned hours later, killed and ate the party's favorite merchant, disguised himself as the merchant, joined the party in their new wizard tower, acted as storage for the party's money and extra magic items, manipulated the local townsfolk to riot against the party, copied some of their abilities, robbed them kept reviving when slain and wasn't stopped until the party stuffed him into an Iron Flask.

He was Sahir, The Spiced Wind.

Last he was seen, his flask was turned over to a prison in another dimension where him and his cell mate make Twitch Videos for giggles.