Vision and the Scarlet Witch #2 (1982)

Robert Frank goes to Wanda, Pietro, and the Vision for help to get custody of his son, Nuklo, in the hopes that the Inhumans are better suited to finding a cure for his mutation. Even though the twins now know Frank is not their real father, Wanda takes pity on him and agrees to help, feeling it's best to let Frank keep believing the lie. When Wanda and Vision go along with Frank to the hospital where Nuklo is being cared for, the head of the nursery, Dr.Bishoff, reveals himself to be the Whizzer's old enemy, Isbisa. He had been using his machine and a special containment suit to slowly siphon off Nuklo's energy to empower himself and seizes the moment that Nuklo is to be taken away to attack and enact his revenge. During the battle, the Vision attempts to phase his arm through Isbisa, but it ends up melting his arm and forces him to amputate it. In his frustration, the Vision reveals to the Whizzer that Wanda isn't really his daughter. When Wanda explains, Frank is touched that they would risk everything for him even without the blood ties. Despite his age, the Whizzer attacks Isbisa with everything he has for the sake of his one, true son, and is mortally wounded. After that, Nuklo, Vision, and Wanda rally against Isbisa, damage his suit, and cause a final dispersal of energy that leaves both Isbisa and Nuklo depowered. In the climax of the fight, the Whizzer passes away, still believing in his children in his final moments.