Warning! Spoilers ahead for Venom #200
In the new landmark issue of Venom, it's revealed that the Marvel's next big threat is the return of the Ultimate Universe. Despite the belief that it had been destroyed during Secret Wars, Earth-1610's evil Reed Richards has found a way to get back to his home universe, protecting himself in the Ultimate Venom symbiote. Now, Eddie Brock fears that he's coming for the primary Marvel Universe (Earth-616), seeking to invade in order to restore his own universe back to its former glory.
Created in the early 2000's, the Ultimate Universe was a fresh and grounded new take on Marvel's various characters, existing as a parallel Earth to the primary 616 universe. In this universe, Peter Parker was still in high school and was eventually killed by the Green Goblin, making way for Miles Morales to step in as the new Spider-Man. The Avengers were a team known as the Ultimates, led by an Ultimate Nick Fury modeled after actor Samuel L. Jackson (eventually inspiring the MCU's casting of Jackson himself as Fury). Furthermore, the Fantastic Four fell apart with the corruption of Reed Richards, who began calling himself the Maker. However, the death of the multiverse saw the survival of the primary 616 coming at the cost of the 1610, though the end of 2015's Secret Wars saw a handful of Ultimate characters being integrated into the main Earth, such as Miles Morales and the Maker. That being said, this dark Richards recently found a way back to his universe, albeit in state of destruction and chaos.
Now, Eddie Brock has become the King in Black, displaying an impressive level of omnipresence/omniscience in Venom #200 from Donny Cates, Ryan Stegman, JP Mayer, and Frank Martin thanks to his vast connection with the universe's symbiotes. Using his new powers, Eddie speaks to all of the major teams of heroes all at once, warning them about the Maker. Brock's been unable to locate this version of Reed, and fills the teams in about what he's been up to and what he's capable of, including Richards' use of the Ultimate Venom symbiote to make himself even more powerful.
According to Venom, Eddie believes that the Maker is going to try and invade Earth-616 in order to restore his own universe, which will then earn him a spot on the multiversal Council of Reeds, an inter-dimensional think tank of sorts comprised of various versions of Reed Richards. In Venom's mind, the Maker is no joke, hence his meetings with the likes of the Avengers, X-Men, Guardians of the Galaxy, and the Silver Surfer all at once. They all need to prepare and be ready, though while the new King in Black offers his services to fight when the time comes, he does turn down Captain America's offer for Venom to join the Avengers.
Cleary, Eddie is doing the right thing by alerting the universe's greatest protectors and heroes. The Maker is just as brilliant as any other Reed Richards, though he's particularly more brutal, willing to do truly horrendous things in the name of achieving his goals. Here's hoping Venom and his allies will be prepared when the Ultimate Universe tries to flip the script, looking to survive at the cost of Marvel's 616 Universe.