Riven

"When she speaks... Do. Not. Listen."

- Kalli speaking to the Guardians about Riven

Riven of a Thousand Voices is a powerful Taken Ahamkara that formerly served Mara Sov within the Dreaming City. She now corrupts the city from its heart, the Keep of Voices, and worked her way into Uldren Sov's mind like a parasite, warping his will in an attempt to open the gate to the Dreaming City and enable herself to enter the material world. She will use what ever is needed to get what she wants and does it without compromise. She is the true main antagonist of Forsaken, and the final boss of the Last Wish raid.

Accompanying the Queen
Riven was born as one of the last remaining Ahamkara in the Solar System around the time of the Great Ahamkara Hunt. She was found by Uldren Sov and presented to Mara Sov. Through the years, she grew and accompanied Mara Sov in her ventures, becoming one of the most trusted and significant members of her entourage.

Becoming Taken
Shortly after the Battle of Saturn, Oryx, the Taken King raided the Dreaming City alongside his Taken forces, where he quickly took Riven as part of his army. She remained within the Dreaming City, having become an incredibly powerful weapon of Oryx at the time - to the extent where her mere status as a Taken drove the Nine into a complete frenzy.

A New Master
Following Oryx's death, Savathûn assumed control over the Taken, which included Riven. Riven quickly became one of the most prominent leaders of Savathun's Taken army, and she somehow retained her will, using it to corrupt the Dreaming City from deep within, along with the mind of Uldren Sov, who had ironically been the one to originally discover her as an infant many years prior.

Forsaken
Ultimately, thanks to the actions of Uldren Sov, the gates to the Dreaming City would be open, allowing Riven the chance to break free of the Dreaming City. Though the Guardians and Reef agents ended Uldren and destroyed Riven's agent, the Voice of Riven, Riven herself remained a threat that the Awoken know had to be dealt with immediately, especially since she was now Taken. Pleading the Vanguard and Guardians for aid, the Awoken succeed in gaining the support they need to launch an assault upon the corrupted Dreaming City and end the Taken Ahamkara.

A Guardian Raid team was formed and breaching past the Awoken Watchtower into the City, the Guardians battle the Taken-corrupted Techeuns: Kalli, Sedia and Shuro Chi. Not only were they successful in defeating the Taken Techeuns but were able to actually free them from the Taken's influence. Gaining their aid, the Guardians finally confront and battle with Riven. The battle takes them throughout the Dreaming City and Ascendant Plane but were able to severely wound Riven. Ensuring the Ahamkara never becomes a threat again, the Guardians enter within the Ahamkara herself and steal her heart, taking the relic back to the center of the City and cleanse it, both purging the majority of the Taken corruption and ending Riven once and for all.

This was, however, exactly what Riven wanted. As an Ahamkara, Riven was able to survive death in a way, and shortly after dying granted one last wish that caused the Dreaming City to be Taken.

Traits
As an Ahamkara, Riven is a calculating figure and a master of manipulation. She sadistically enjoys driving one into complete madness, as she did with Uldren Sov through speaking to him in his head under the guise of Mara Sov. Additionally, Riven possesses disturbing abilities and a terrifying level of cunning that is only rivaled by her master, Savathûn. Her mastery of corruption directly led to the death of Cayde-6, and the events of the entirety of Forsaken as a result.

Riven has retained her free will even after being Taken.

Like the rest of her kind, Riven is a shapeshifter, and typically adopts reptilian or dragon-like forms. After becoming Taken and corrupting the Dreaming City, she confronted the Guardian as a gigantic clawed and tentacled serpentine beast, with a head covered in numerous eyes and protected by bony folding plates.

Trivia

 * Though she is Taken, Riven is the first Ahamkara ever observed in the Destiny series.
 * Riven is the second Taken entity that retains a sense of free-will and independent thought. The first being Malok.
 * She is the first female final Raid boss.
 * It is not elaborated on if she was actually the Voice of Riven, or if it was some sort of servant or projection of her being.
 * Riven's epithet, "of a Thousand Voices," is reminiscent of that of the Worm God Xol, the "Will of the Thousands". It is unknown what significance this similarity has, if any.
 * Riven is by far the largest Raid boss in Destiny history, surpassing Argos, Planetary Core and Oryx, the Taken King.

List of appearances

 * Destiny 2
 * Forsaken