Definitely. Power met her end in the Chainsaw Man manga. This event brought about changes in the dynamics among the characters and moved the story forward in an unexpected way.
Power dies in a climactic and intense moment in the manga. It's the result of a series of events and confrontations that lead to her ultimate sacrifice.
Well, there are some deaths that come as surprises and are crucial to the plot's development. But I suggest you explore the manga to experience the full impact.
Makima is also a key character. She is a mysterious figure who seems to be in control of a lot of things in the world of Chainsaw Man. She has an alluring yet somewhat intimidating presence and her motives are not always clear, which makes her a very interesting character.
Denji is an important character as he is the Chainsaw Man. Makima is also crucial. She has a mysterious aura and a lot of influence within the Public Safety Devil Hunters. Aki is another significant character. He is a devil hunter who has his own vendettas and goals. Power, a fiend, is important too. She teams up with Denji and has her own unique personality and powers.