Valerian walked out of his shack, but his mind was filled with images of what happened last night. Shiba had come to him last night all of a sudden and asked him directly to help her. The reason she was so forceful was also made clear by her.
Old man Fern was nearing the end of his life. He was too old. Valerian was surprised at first but when he got to know things in great detail, he understood what was going on here. Turns out that Clar-awks were magical creatures, they all had a mana core that would naturally deteriorate and will crumble apart.
Once the magic core crumbles, even a person who seems to be at the peak of his health would pass away. This was the cruelty of nature. You can have a longer life span, but it will still come to an end. Nothing in this world was eternal or infinite.