The end of the first arc of Chainsaw Man brought an almost complete reset of the status quo, with pretty much every major character, aside from Denji, slaughtered. One of the characters to get the chop was the terrifying Control Devil Makima. To the dismay of many readers, another was Power, the weirdly lovable Blood Fiend who forced her way into the position of fan-favorite character. And while death can be something of a revolving door in the world of Chainsaw Man, there is no doubt that the consequences of this first arc will play out in a tragic way.
Throughout the first arc of Chainsaw Man, Makima is presented as an absolutely terrifying monster, an avatar of death and destruction. She forces Denji to kill Aki in the most heartbreaking way possible, and then promptly follows up by killing Power, Denji's closest friend. It's difficult not to root for her downfall at the end of the series -- and what a downfall it turned out to be.
Chainsaw Man Part 1's Ending Gives Makima a Chance for Redemption
Makima, however, was given a chance at redemption... sort of. Devils don't die; rather, they're killed and constantly reincarnated, alternating between lives in Hell and lives on Earth. Sure enough, shortly after Makima's death, the Control Devil quickly found herself reincarnated on Earth in the form of a girl named Nayuta. She was entrusted to Denji to raise up and ensure she doesn't go bad in the same way Makima did.
What Chainsaw Man made crystal clear is that, while Nayuta might be similar to Makima -- perhaps too similar -- she is not Makima. She's a reincarnation, not a reproduction, and she will never be the same person as Makima was.
It's difficult to be overly sad about that, considering how awful Makima was. What is sad, however, is what the development meant for Power. One of the highlights of Chainsaw Man is the relationship between Power and Denji. Throughout the first arc of the series, they go from viewing each other simply as tools to get what they want -- Power seeked to sacrifice Denji to save her cat Meowy, while Denji, um, wants to touch some "boobs" -- to having a close, and moving, relationship.
Most of this wasn't conveyed through dialogue or even action but, instead, through body language. There was a physical closeness, with Power constantly resting her head on Denji's shoulder or practically laying on top of him when they sleep, conveying their emotional bond.
Power's Death in Chainsaw Man's Ending Resonates
Chainsaw Man is, in many ways, a very nihilistic comic. It's a dog-eat-dog world in which beloved characters die for odd and unfair reasons, simply because they weren't strong enough. It's a hyper-violent visual freakout, and shouldn't be taken too seriously -- after all, the hero has a chainsaw for a head. But what makes Chainsaw Man special is its heart. Even though these characters are hyper-vulnerable, it's impossible not to care for them, because they care about each other.
Aki cared about his "buddies," his found family of Devil Hunters. That even extended to Denji and Power, even though they're probably the most annoying people possible with whom to share an apartment. Himeno had a powerful unrequited love for Aki; Power saw Denji as her first and only friend and relied on him for security and comfort. And all of these characters not only care deeply about each other, they were also willing to die for each other.
This is why Power's death resonates, and why the nature of Makima's reincarnation is so sad. In her final moments, Power tasked Denji with finding the Blood Devil in Hell and killing it, so she can return to Earth, become a fiend once more and resume their friendship. But Makima's reincarnation shows that even if the reincarnated version of the Devil is similar, it just isn't the same as the original.
So, is Power gone for good? Perhaps, perhaps not. If she was a Devil being reincarnated, then there is no way she could ever be the same Power that we all know. But Power is a Fiend, maybe things work differently for them than for straight-up Devils. The rules surrounding Devils and Fiends are murky at best, and the Chainsaw Man definitely has unknown levels of power himself that could change things all the more.
For the time being, however, Power is definitely gone, and it seems like no matter what she or Denji believes, she isn't coming back in Part 2 of the manga. At least, not unchanged.