Jander Sunstar was born to gold elf parents on the island of Evermeet. He was struck by wanderlust and headed to mainland Faerûn in search of adventure. He found more than he'd expected. Whilst in Merrydale, the original pack of vampires which infested the area for years to come attacked. Jander was betrayed by a friend who had been transformed in the first battle between the dalesmen and the vampires. Now a vampire himself, Jander was bound to the will of his new master, Cassiar, for over a century, but never surrendered his soul to his master's evil ways. He tried to survive on animals instead of humans but Cassiar's orders caused him to perform many evil deeds. Eventually, he managed to kill Cassiar in Mistledale in the middle of Marpenoth of 892 DR with the help of his friend Rhynn Oriandis.
He wandered Mistledale for a while, preying on bandits asleep in the wilderness but not killing them, just drinking a little from each in their group. One night though, the group he was following were alerted to his presence and he had to flee. When he stopped, he encountered Eldath who offered him sanctuary in a holy grove of Silvanus. For as long as he didn't leave the grove, he would be a mortal elf again, though sunlight would still be deadly. He met a priest of Silvanus from a nearby abbey, coming to draw water from the sacred pool and the two became friends. The next night, wood and antlers were on the ground and, seeing it as a sign, Jander whittled them into statuettes of Eldath and other shapes which he gave to the priest for his abbey to sell. Jander was extremely happy with this life until one night when he saw that the abbey was on fire. His new friend struggled to the grove saying that they were under attack but Jander should stay in the grove lest his divine absolution be revoked. Jander couldn't take the sight of thugs beating his friend and left the grove, using his returned powers to slaughter them and saving the lives of many of the abbey's residents but when he tried to return to the grove, he found that he could not, a painful, invisible barrier prevented him from returning and he doubted Eldath would offer him succor twice.
Jander left the Dalelands and his memories behind that night, heading for [Waterdeep]]. He settled outside of the city and when feeding on animals wasn't enough he fed on inmates at an insane asylum. He fell passionately in love with one of them though, a beautiful human woman named Anna, cursed to never age or be free of her madness. Anna fell deathly ill with fever in 1098 DR and Jander offered to turn her into a vampire to save her but she refused. She died in his arms and in his rage and grief he slaughtered the other asylum inhabitants, setting the building on fire and swore revenge on whatever caused Anna's madness.
The Dark Powers of the Demiplane of Dread heard his plea and whisked him away to their awful realm. Almost immediately, he came into contact and conflict with Count Strahd Von Zarovich of Barovia. He learned that Anna was once known in Barovia as Tatyana and was the lover of Strahd's brother Sergei. Strahd murdered his brother and drove Tatyana to madness in his attempts to make her his. She threw herself into the ever-present Mists of the plane and an aspect of Taty"ana" arrived in Waterdeep, where she was committed and met Jander.
25 years later, Jander and Strahd were bitter enemies, knowing he had found the object of his revenge, Jander came to hate the darklord of Barovia with all his heart. With the aid of two brave villagers, a priest and a rogue named Sasha and Leisl, he attacked Strahd, even offering Lathander his life in exchange for victory though both vampires survived the confrontation, severely wounded. Jander believed himself to be dying and asked his friends to let him see the sun rise one last time.
Certain Faerûnian sages claim that the Mists of the realm blocked the sun's glare from destroying Jander and he awoke in the area of the Demiplane known as Forlorn. He is now a vampire hunter by trade, sharing the hatred he still has for Strahd to all of his unwanted kin and if he ever returned to Toril, he would likely perform exactly the same service.