The first time we meet Unity, T'Charr and Terataya combine to battle M'Shulla, a Lord of Chaos. T'Charr and Teratraya are the Lords of Chaos and Order respectively who grant power to Hawk and Dove. As most of their power is diverted into the pair, M'Shulla easily defeats Unity.
After a pair of missions where Dove retrieved a vial of chaos from the essence of Kestrel absorbed by the Hawk from Ren Takamori and the theft Hawk committed of a sapphire with the power to resurrect (a gem of order) from the Smithsonian Museum, Barter gives a young, female neurosurgeon (that Waverider has appear) these items. She uses it to become Unity. The young woman is Dr. Arsala, the daughter of Hank Hall and Dawn Granger from an alternate future raised by Ren Takamori and Captain Brian Arsala ("Sal"). She is powerful enough to face the Monarch alone.
Unity may not have survived the 9th Age of Magic.