WARNING: The following contains spoilers for Sinister War #4, on sale now from Marvel.
The "Sinister War" event has been filled to the brim with Spider-Man's deadliest foes. In orchestrating this massive event, Kindred has been trying to show Spider-Man that some people are beyond redemption. Even so, in Sinister War #4 by Ed Brisson, Nick Spencer, Mark Bagley, Dio Neves, Marcelo Ferreira, Andrew Hennessy, Andy Owens, Brian Reber, Andrew Crossley and VC's Joe Caramagna, Boomerang surprised Kindred by sacrificing himself to save Spider-Man.
Boomerang has been on the path of redemption since 2018's Free Comic Book Day: Amazing Spider-Man, by Nick Spencer, Ryan Ottley, Cliff Rathburn, Laura Martin and VC's Joe Caramagna, when Fred Myers moved in with Peter Parker. Although Peter was hesitant to live with a known supervillain, the two eventually grew closer. As a result, Peter saw the good man that Boomerang could be and was trying to become. On a few occasions, Spider-Man and Boomerang even worked together. For example, the two teamed up in order to track down the Lifeline Tablet and keep it from the Kingpin's clutches.
Unfortunately, by 2021's Giant-Size Amazing Spider-Man: King's Ransom, by Nick Spencer, Roge Antonio, Carlos Gomez, Ze Carlos, Alex Sinclair and VC's Joe Caramagna, Boomerang betrayed Spider-Man. After finding the Lifeline Tablet, Spider-Man was ambushed by Boomerang and his own Sinister Six, who handed the tablet over to the Kingpin.
In truth, Boomerang had been working for the Kingpin since he moved in with Peter, using the wall-crawler to find and secure the Lifeline Tablet. Of course, Fred still felt a fair amount of guilt over betraying Spider-Man and Peter, especially after befriending both of them. At an earlier point in "Sinister War," Boomerang even told Spider-Man to run, while he made the other villains believe that the web-slinger had escaped from his clutches.
In the most recent issue of Sinister War, Boomerang demonstrated his loyalty to Spider-Man when Fred sacrificed himself for the web-head. At the time, Morlun was trying to drain the life from Spider-Man. Heroically, Boomerang jumped in between the two of them, telling Spider-Man to run once again.
To Spider-Man's horror, he saw Morlun drain Fred of his life force. Ultimately, this sacrifice goes to show how far Boomerang has come as a character. Fred's actions are a far cry from the Boomerang that initially moved in with Peter Parker. Before, Fred Myers would have sold out any one of his crew for even a small reward.
At this point, it was hard to imagine Boomerang sacrificing his life for anyone, let alone Spider-Man. Over time, however, it seems that Spider-Man's heroism really rubbed off on Fred. Boomerang may have set out to use Spider-Man for his own gain, but over time, he grew to like both Peter and Spider-Man.
Fred grew so attached to Spider-Man that he couldn't just stand by and watch as the web-slinger was mercilessly killed in front of him. Overall, Boomerang's sacrifice went to prove Kindred wrong. Fred demonstrated that people can change and that Spider-Man's enemies were not beyond redemption after all.
Additionally, Fred's move inspired some of his colleagues, such as his old Sinister Six. After witnessing his death, Boomerang's crew turned on their fellow villains, showing a clear loyalty to their friend. Boomerang's path to redemption was far from perfect, but in the end, Fred Myers' sacrifice gave hope for all of Spider-Man's villains.