Her skin is paler than most humans, but does not yet seem to have succumbed to the deathly grey tone that most of her Ebon Knight cohorts have. She has not revealed why this is the case. It's been postulated that her previous magic use in life may be causing the lack of decay. Her hair is a deep shade of auburn, and it hangs down just past her shoulders, neatly styled. Her eyes glow with the same eerie blue glow common to Ebon Knights.
When ungeared, she prefers to dress in simple pull-over shirts and slacks. She is fond of the color purple, and even while geared you can see her purple shirt underneath where her armor does not cover her. When not wearing the tabard, she wears a signet pin with the logo of the Argent Crusade.
Tanya values peace above all else, and will go through great lengths to achieve it. She has been known to offer truces to members of the Horde in the hopes of staying an attack on Alliance soil. Because of this belief, she is not fond of King Varian Wrynn, but feels there is hope on the horizon when the time of Prince Anduin's coronation comes.
Sometimes she can have a temper, and if she is pushed hard enough, she will strike back. Her reactions when her temper flares up have only gotten more intense since becoming undead, but she is working on controlling them.
She also has a pet peeve against bigotry and prejudice, as she herself has been the subject of such over the last couple years. Because of this, she was one of the first to speak up against anti-Worgen bigotry among the Alliance.
Otherwise, she is very personable for an Ebon Knight, and enjoys pleasant conversation.
Bretanya Marxworth was born in Brill just as the First War was starting, back when Lordaeron was still a human kingdom. She and her younger sister Halcalya were born into a family of well-to-do scribes going back for generations. Having grown up in Lordaeron, she was mostly shielded from the effects of the First War, taking notice of it only when she lost a lot of her friends that moved back to (New) Stormwind after its rebuilding.
Not wanting to take up the family inscription business, and still longing for many of the friends she lost, Tanya announced as a teenager that she would be moving to Stormwind to receive training as a warlock full-time. Her parents were surprised at this news, but decided to support their elder daughter in her life choice. After packing her essentials, she boarded a gryphon flight to Stormwind.
Tanya learned her class effectively, putting her full efforts into her training for years, but the test of her training came when she received word that Lordaeron was under attack by the Scourge. Terrified about what may have become of her childhood home, she caught the next gryphon flight back to Capital City to fight in its defense.
For a lot of the battle, Tanya was holding her own, often taking on mutiple Scourge soldiers with just herself and her voidwalker, but the Scourge, fed by the deceased of Lordaeron, just kept coming in numbers too large to effectively fight against. Frantically spellslinging at the growing numbers of Scourge around her as her battlemates died and were resurrected as Scourge one by one, Tanya was herself killed by the Scourge.
The Death Knight Arthas Menethil saw some promise in the young warlock, and ordered her body taken back to Acherus instead of being immediately resurrected. After her arrival at Acherus, the Scourge resurrected her to become one of the Lich King's Death Knights.
As a Death Knight of the Scourge, Tanya's will was not fully hers, often controlled by the Lich King to do his bidding. She presently describes the experience as like being a passenger in her own body. After many years as one of the Scourge, she was ordered to strike at Light's Hope Chapel with a batallion of Death Knights numbering in the thousands. This battle was simply to bring Argent Crusade leader Tirion Fordring out of hiding, and once Arthas, now the Lich King himself, admitted this batallion of Death Knights was simply used as bait, and therefore expendable, the batallion turned on him, forming the Knights of the Ebon Blade.
For the next couple of years following that incident, Tanya served the Ebon Knights, and the Alliance, under the command of Highlord Darion Mograine, dedicated to defeating the Scourge at their heart in Northrend. She was not personally among the forces that brought down Arthas, but she lended herself to weakening the Scourge in other areas, including the leftover Scourge that remained after Arthas' death.
After finishing up her tour in Northrend, Tanya, unable to truly go home again due to Lordaeron's current alignment with the Horde, settled down in Goldshire, a town that often reminded her of old Brill. It was there that she received correspondence from her sister, now a warlock with the Forsaken.
She met with her sister at the crypt in the middle of the Brill cemetary. During that meeting, she discovered that Halcalya had lost her memory, but was still willing to reconnect with whatever family she had left. Tanya filled Hallie in about her past, and in return, Hallie told Tanya about her works with the Argent Crusade and the Undercity Underground toward a lasting peace. Inspired by her sister's deeds, Tanya herself soon joined the Argent Crusade, and her sister's current movement "Occupy Azeroth", which supports the removal of corruption in all factions. She and her sister are the main Alliance and Horde contacts, respectively, for the cause. The movement is far less popular among the Alliance than in the Horde, as Tanya has been often threatened with charges of sedition.