Crisis on Infinite Earths #5 (1985)

In the Antimatter Universe, a dark, malevolent force addresses his new playthings, Psycho-Pirate, the Flash and the Red Tornado. He has Psycho-Pirate use his emotion controlling abilities to keep the Flash in line, while also promising that he will soon have his own worlds to rule. On the Monitor's satellite, Harbinger regains control of her mind, and realizes what she has just done. She has just killed the Monitor. Pariah is present, and tries to get some answers from her, but Harbinger has no memory of the attack. Suddenly, a view screen activates and a pre-recorded image of the Monitor addresses both of them. He tells them that he knew of his eventual demise at Harbinger's hands, and bears her no ill will. To safeguard the remaining universes, he turned his body into an energy conduit. Upon his death, the Monitor's life essence shunted Earth-One and Earth-Two into a Netherworld, keeping them safe from his adversary's attack - at least for now. However, in his haste to save them, all time has become one. Alexander Luthor enters the chamber and hears the last of the Monitor's speech. On Earth-One, varying timelines begins to intermingle with one another. Dinosaurs and World War I era bi-planes exist side by side with modern day Metropolis skyscrapers, and strange vessels from the far-flung future. Amazingly, Earth's populace remains relatively calm - another side-effect of the Monitor's influence. Back on the Monitor's satellite, Alex, Pariah and Harbinger summon together a massive congregation of heroes from Earth-One and Earth-Two. They explain the present situation, but also explain that in order for things to correct themselves, the Multiverse must be folded back upon itself and become a single universe once again, or else all worlds will be destroyed. On Earth-One, other heroes continue to help out amidst the confusion. Batman invites a group of heroes and villains into the Batcave for consultation. Starfire and the Legionnaire Sun Boy fly to Russia to help Red Star tackle a dinosaur. Members of the Green Lantern Corps fly to Oa to seek aid from the Guardians of the Universe, but the Guardians are swept up in an unforeseen attack. Rip Hunter and the Time Masters try to solve the mystery of the inter-connecting time lines. Wildcat saves a little girl from crumbling debris, but his legs are crushed in the process. Meanwhile in the Antimatter universe, the unseen enemy takes control of the Red Tornado and reconstructs him to do his bidding. He turns him into a force of primal energy and sets him upon the Earth. As the Red Tornado storms across the country, Earth-One and Earth-Two begin to slowly merge together. People see ghost-like astral images of people from the parallel worlds. The Flash overcomes Psycho-Pirate's control and demands to see the face of the being who abducted him. The enemy steps forward and introduces himself as the Monitor. This Monitor however, is not the same as the one who just died. Unlike the more human-looking Monitor, this one is a gruesome alien with blazing red eyes, and jaundiced yellow skin.