I think Nef definitely could not save the king with Doctor Blythe, even if she could fix broken DNA. I think there's a much better chance that the King could save himself, if he had absorbed Nef. It all comes down to whether he could fix his DNA as quickly has the dangerous isotopes in his body damaged it. But we'll never know. Gon smashed Neferpitou's skull in! Neferpitou is dead!