Sylvanas was a High Elven Ranger of Quel'Thalas (until it got destroyed). Arthas turned Sylvanas into a banshee when she begged for a painless death. Knowing how Arthas is, she was not spared. Sylvanas had a pure heart but not pure enough to stop to be possessed by Arthas. She eventually broke free of the curse and tricked Garithos into helping her save non-human lives. When the deed was done, she commanded Tichondrius to give Garithos the painful death he deserved.