Then, at the WoTLK Classic Gold conclusion of the Sanctum of Domination, the Jailer, the villainous big-name Sylvanas has been working on, achieves his aim of obtaining the symbolism of the various worlds in the Shadowlands increasing his power and receiving a wardrobe change as a result. The Jailer opens a portal to...somewhere and instructs the different people from Azeroth in attendance, as well as Sylvanas to kneel to help him in his plan to destroy and then recreate reality.
This causes Slyvanas the wrong way. She has been willing to serve the Jailer until this point, but witnessing the Jailer's use of an enlightened Anduin Wrynn, she is reminded of being forced against her desire to serve Arthas in the past, when she was killed and transformed into a banshee in World of Warcraft. Sylvanas shoots an archer at the Jailer with anger and declares she will "never let him serve." The Jailer then decides to (checks notes) honor her by offering Sylvanas her soul back, that was stolen by Arthas via Frostmourne many years back. The Jailer says that he'll leave Sylvanas to the fate of the Jaina Proudmoore Thrall and Bolvar Fordragon, before proceeding to enter his magical portal with Anduin at his side.
There are a number of reasons why this story has been a bit controversial. First, Sylvanas in the past several expansions has been guilty of some pretty heinous crimes in her quest to collect souls for the Jailer, including , but not only:
Beginning a buy WoTLK Gold full-blown conflict with the AllianceBurning up the huge tree Teldrassil that is the reason the Night Elves called homeKilling Horde leader Varok Saurfang in his effort to remove Sylvanas as leader in the HordeKidnapping and beating leaders of the Horde and Alliance