Xenia Onatopp was born in Georgia, before the fall of the Soviet Union in the late 80s and early 90s. Trained and working for the KGB, she flew missions as a fighter pilot, racking up experience and skills that would be useful in later employments. At some point, she also perfected her now-notorious method of killing - Crushing her lovers between her thighs, often during the act of sex.
When the Union fell, Xenia was out of a job, and, at some point was brought into the Janus Syndicate's inner circle, alongside Alec Trevelyan - a former MI6 agent, and General Arkady Gregorovich Ouromuv, a eventual turncoat within the Russian Government. It is a possibility that Onatopp and Ouromov were already acquainted, given their mutual affiliation before the fall of the Iron Curtain.
"How do you take it?"
"Straight up, with a twist."
--James Bond and Xenia
When the Syndicate moved their plan to use the Goldeneye Satellites into motion, Xenia was dispatched to Monte Carlo, to seduce and murder Admiral Chuck Farrell. However, she encountered secret agent James Bond along the way, and, in a race between her F355 Ferrari and his Aston Martin DB5, indulged in a playful chase that Onatopp won, thanks to the chagrin of Bond's passenger.
They crossed paths again, however, in Monte Carlo's casino, where they played against each other in a game of Baccarat. Onatopp eventually lost, and was privy to Bond's usual attempt at seduction, but, in a twist on the usual formula, Xenia left with Admiral Charles 'Chuck' Farrell, a member of the Canadian Navy. On board the Manticore Motor Yacht, a boat owned by the Janus Group, Xenia and Farrell, after unwittingly being observed by Bond, indulged in a dangerous sexual encounter, that came to a close when Xenia crushed the unwitting man between her tightly toned thighs, achieving sexual arousal and eventually orgasm in the process. Using a Janus-employed double of Farrell, Onatopp then attended a presentation the next day aboard the La Fayette destroyer, where the new, electro-magnetic-pulse-proof Tiger helicopter was being tested. There, despite Bond's attempts to interfere, she escaped with the newly made flying machine.
In Severnaya, Russia, the Goldeneye controls were held by several members of the Russian military. With Ouromov, Xenia went to retrieve them. No survivors remained, Xenia kills all the technicians and soldiers present - Save Boris Grishenko, another Janus turncoat. Destroying the Severnaya facility using one of the Goldeneye satellites, Onatopp, Ouromov and Grishenko escaped in the Tiger - the only machine shielded from Goldeneye's electromagnetic blast. Next, when Natalya Simonava survived the destruction of Severnaya, Xenia and Boris were sent to stop her spreading word of the truth. Then, after Bond had arranged a meeting with Janus, investigating the theft of the Tiger and the detonation of Goldeneye, Xenia went to meet him.
In the sauna of Bond's hotel, the Grand, the two indulged in a kinky bout of foreplay, Xenia alternately loving and beating the secret agent, until, clad in a simple bathrobe, she got into his lap, and wrapping her bare legs around him, began to crush him, achieving yet another orgasm in the process. Fighting back, Bond only earned himself kisses and more crushing, until he finally freed himself, forcing Xenia to take him to Janus.
"This time, Mr. Bond, the pleasure will be all mine!"
Their final encounter is when Bond and Simonova get shot down by plane and Xenia checks out the wreckage. Onatopp rappels from a helicopter onto Bond, who is just awakening, and quickly gains the upper hand in their battle. She gets Bond into position to crush his chest; just as Bond is ready to pass out from the pressure, he connects the rope she rappelled down to her safety harness, grabs her AK-74 rifle that was slung across her back and kills the helicopter's pilot by shooting into the helicopter's cockpit from the ground.
The chopper veers away, pulling Onatopp off Bond and trapping her in a fork of a tree, with her chest being crushed by her safety harness. She struggles to breathe in her crushed state. Xenia's body goes limp as dies just before the chopper crashes. After Onatopp's death, Bond tells Simonova that, "She always did enjoy a good squeeze."