I am scared for Asa …

Asa is determined to save Denji because she believes that if she separates him from Pochita, he could live a human life again, which Denji doesn't really want, but that's another topic in itself

So the people who tried to save and rescue Denji all get the same fate and it never ended well for them, they all died or at least lost their autonomy, in Pochita's case, and it's kind of a law in Chainsaw Man that saviors die, considering that most of the characters died on their way to save someone.

Pochita gave up his autonomy to revive Denji and replace and function as his heart now

Aki to tried to keep Denji and Power save and trapped in Makima's trap

Power sacrificed her remaining blood to revive Denji, leading to her death

Nayuta fought against the mob, to get time that Denji could escape from the angry mob, leading to her demise

Honorable mention would also be

Himeno using the full maximum of her contract to keep Aki save from Katana Men, leading to her death

Angel trying to save Aki from Makima‘s brainwashing and ending up as Makima‘s puppet and demise

Asa Mitaka‘s Mom, who tried save her daughter by shoved her away out of harm, costing her own life

Yuko, who mutated into a devil through a contract and killed the bullies to keep Asa save from them, which resulted in her permanently demonic appearance and her dying on the way for searching for help

So things look bad for Asa Mitaka … I hope she gets the main character plot armor