Ultimate Fantastic Four #19.
Rhona is able to take each member of the four one by one and lastly subdues Reed. Taunting the drugged Reed she attempts to explain her actions and injects her memories into Reed's brain upon which he sees why she has taken control of the Baxter Building. After being rejected from the Think Tank for her borderline psychotic tendencies, Rhona returned home and created a serum to enhance her brain capacity, and later surgically removed parts of her brother's brain and grafted them onto hers in order to further enhance her mental capabilities. After Reed views these memories, Rhona begins an international auction to sell the Fantastic Four to the highest bidder, which ultimately is won by the Latverian bidder for 900 million dollars. When attempting to transport the team, the helicopter that had crashed before becomes dislodged and crashes down giving Reed a chance to escape and remove the tranquilizers that have kept the other members unconscious. After a brief battle, Rhona is able to escape with her android Robbie by using a holographic projector that creates multiple versions of her.Later, Rhona is hired by AIM, Advanced Idea Mechanics, to steal Cerebro from the X-Men which she does by using an alien message to distract most of the team away from the X-Mansion and then taking out Iceman, Wolverine, and Kitty Pryde. She is able to convince the three X-Men that the Fantastic Four were the perpetrators. Rhona shows her true colors when she kills the AIM agents who were sent to retrieve Cerebro and instead shows that her intention was to use Cerebro to enhance her own mental capabilities even further. Meanwhile the X-Men have been battling the Fantastic Four and at this time Rhona reveals herself as the culprit. Teaming up in order to stop Rhona, both teams locate Rhona and attempt to stop her. Rhona is able to mentally subdue them easily, but Reed reprograms Cerebro to give Rhona an enhanced sense of empathy instead of knowledge and she is attempts to flee after being thwarted by Reed. Her escape plane explodes after Wolverine sabotages it. Her whereabouts are unknown at this time.