Oksanna was originally the human Lady Takashi's mother, whose consciousness was claimed in her sleep by Sythorr as her body died and was grown into a Haluu plant. Her name "Oksanna" was a corruption of the Japanese word "okaasan", which meant "mother". Much of her mind was wiped, but she was strong enough to hold onto bits of her old life and kept a human form. Lady Takashi called for her mother, and Oksanna contacted her psychically in a dream where she came to the garden along with an expedition team. Oksanna helped feed most of the team to Sythorr as part of his plan to spread his seeds to Earth to take it over. Using the Dreamspace, the Twelfth Doctor showed Oksanna the truth and, remembering her old life, Oksanna embraced her daughter.
As an act of atonement, Oksanna helped Takashi, along with the Doctor and his friends, to escape and activated the robotic Keeper's self destruct mechanism, causing an explosion that destroyed the dome, along with Sythorr and the rest of the creatures. (COMIC: The Soul Garden)