User blog comment:Xilinoc/Ch. 557 - He Already Set His Life Aside/I Already Threw Away My Life/@comment-1387259-20131113144349/@comment-11051098-20131113145017

Mangastream's translation had Sajin saying that the secret technique "allows us to temporarily obtain immortal bodies". According to that, he will revert from his immortal form, but whether his heart is lost forever, isn't clear.