Champions of the Omniverse: Part 12

Returning to the void of Eon once more, our heroes find their wounds healed and their original memories returned in their entirety. The team are unable to tell just how much time has passed when they are called upon again to enter the time stream and set things right. Our heroes awaken around the meeting table in the Avengers Mansion, Sonic Tsunami is about to call the meeting to order. Before the Avengers can begin to discuss upcoming charity works, a cloud of smoke begins to fill the room. The team stands back and readies themselves when Sonic Tsunami shouts "Avengers Assemble!". The smoke clears, revealing the imposing figure of Immortus, ruler of Limbo!
"Greetings Avengers... I am here to warn you that a catastrophe is about to befall this timeline and I need your help to stop it! ...wait ...are you the Champions of the Omniverse?" 
"Who are they?" Firenado asks. 
"It is what your team will be known as in your personal future," Immortus states grandly, "those of you who survive." 

Immortus goes on to explain that a series of events will lead to the Earth being destroyed in nuclear fire when solar flares detonate ever reactor on the planet. To avoid this fate, Immortus has pulled the Avengers/Champions and the Avengers Mansion into Limbo for protection and so that he can send them out to save the time-stream. Agreeing to help, the team are told that a young man is about to encounter an alien device in 1960 that will increase his intelligence, but cause a tumor that will eventually kill him. The man will grow up to invent a brilliant, but flawed coolant system for nuclear power generation which will propagate the technology over the globe. 

Utilising Immortus' technology, our heroes arrive in Central Park, New York, watching a group of youths playing football, including their target. Given that the Fantastic Four won't debut for another couple of years, give or take, the men are surprised to see a group of costumed heroes, but do not flee in terror; Firenado looking like the Human Torch probably helps. The man the team are looking for wanders over and begins to talk to the team. Things are going well until The Arsonist attempts to place Immortus' Memory-erasing helmet on the man and he dodges with astonishing speed, bursting into flame at the same time. Koga attempts to use hypnosis from his light powers on the young man, and it seems to work with him becoming drowsy. Manzilla prepares to grab their target whilst The Arsonist uses his powers to reduce the fire. In a flash of inspiration, Sonic Tsunami realises that they are fighting Mimic! The mutant is stealing their own powers to use against them. As if on queue, Mimic grows wings and four additional arms and takes to the air, raining fire down on our heroes. Manzilla blasts Mimic with his atomic breath, freezing the mutant in a block of ice and sending him crashing to the earth. The Arsonist slams the helmet on Mimic and the team are drawn back to Limbo to await their next task.