Jonah managed to discover that Amy Minoru had hacked into Wizard's servers. Fearing that she might have discovered video files showing PRIDE perpetrating ritualistic sacrifices meant to keep him alive, Jonah decided to solve this problem. Although he assured his lover Leslie Dean that he would only interrogate her to find out what she knew and frighten her enough so she would not divulge the video in case she had found it, he actually murdered her and staged the scene as if Amy has committed suicide.
Robert and Tina Minoru, both members of PRIDE, were devastated by the loss of their daughter and remained ignorant of the truth behind her death for years. It was only after PRIDE discovered that Jonah had fooled them and they decided to assassinate him that Dean chose to reveal the truth to Robert and Tina. Robert was extremely upset to learn that he had not been able to protect Amy from Jonah and decided to take on Jonah on his own, despite PRIDE advising him against it. To that end, Robert planned to use an Anti-Gibborim Inhibitor of his own making created out of Karolina Dean's Church of Gibborim Bracelet she had dropped during the Infiltration into Minoru Mansion.
Using the fact that the whole security system of the Church of Gibborim Executive Office had been designed by Wizard, Robert Minoru easily sneaked into the office used by Jonah, waiting for him to return after having rigged the room with several Anti-Gibborim Inhibitors. When Jonah finally arrived, Minoru recalled that he had murdered his daughter Amy and that he wanted him to pay the heavy price for it.
Much to Minoru's satisfaction, the inhibitors had a dramatic effect on Jonah, who was left unable to retaliate against Minoru, leaning on the floor and coughing blood as he noticed the devices in the room. Minoru then detailed how he had crafted the inhibitors from Karolina Dean's Church of Gibborim Bracelet and demanded to know where the Runaways were, as PRIDE was still looking for them and knew that Jonah could know about their whereabouts.
Then, in a moment of anger, Minoru violently kicked Jonah in the head, claiming that it was payback for Amy's murder. However, as Minoru prepared to strike a final blow to Jonah, he was knocked unconscious from behind by Aura and Frances, who had been alerted by the office's open door. Jonah thanked them for their assistance and told them that they both made it to the rank of Ultra in the Church of Gibborim's hierarchy.
Despite feeling extremely weak, Jonah decided to return Robert Minoru to PRIDE. Arriving in poor condition at the PRIDE Foundation Facility under the astonished look of the members of PRIDE, he dropped the unconscious Minoru, mocking them for their failed assassination attempt. Jonah then explained to PRIDE that he would not retaliate for this move against him, but that he wanted them to come to assist him in his departure from Earth, or he would kill their children. In return, Jonah promised to tell PRIDE where the Runaways were.
Although Jonah survived the ordeal, it significantly affected his health and accelerated the decay of his host body, to the point that he needed another person to sacrifice to make sure that he would survive. Since PRIDE, even Leslie Dean, refused to assist him, Jonah ambushed Geoffrey Wilder in order to sacrifice him, although the process was ultimately interrupted by the Runaways.
Even if Minoru was unable to kill Jonah, his assassination attempt was proof that the Anti-Gibborim Inhibitors he had created were efficient. The same inhibitors would later be used against Karolina Dean during the Chase of the Runaways.