It could end with the wife passing away but the man finding strength and meaning in the experience. Or perhaps it leads to a twist where the wife's condition wasn't as dire as it seemed.
There was a novel called " The Peak of Martial Refinement ". The main character was Lin Dong, who was accidentally taught inner strength and martial arts by an old man. During his training, Lin Dong encountered a young man with his back facing him. This young man seemed to be the disciple of that old man. Furthermore, the dying person on his back was the old man that Lin Dong had once saved. This young man taught Lin Dong martial arts and inner strength training methods, and Lin Dong began his own martial arts training. This novel was a modern style martial arts novel with ups and downs in the plot and vivid characters, which was loved by many readers.
Infidelity could be a reason. If one partner cheats on the other, it often shatters the trust in the relationship, and the betrayed partner may decide that they can't continue. Also, communication breakdown. If they can't talk to each other about their problems, small issues can turn into big ones, and eventually, the man might feel that divorce is the only option.
It could be due to severe mental illness or untreated psychological disorders that led him to commit such a horrifying act.
The man could be describing his wife's kindness. For example, he might talk about how she always volunteers at the local community center, helping those in need. This shows her selfless nature and big heart.
Perhaps it's a story of how they met. He could talk about the first time he saw her, what she was wearing, and how her smile made his heart skip a beat. Then he could go on to explain how their relationship developed from that initial encounter into a loving marriage.
Maybe the man successfully cuts down the tree and uses the wood for whatever purpose he had in mind, like building a fence.
Well, perhaps he has his own insecurities and fears. Seeing his wife with cancer might make him face his own mortality in a way he can't handle. He might also be influenced by external factors like family pressure or the prospect of starting a 'new' life without the burden of a sick partner. However, these are all rather selfish reasons considering the situation his wife is in.
There could be a breakdown of the family. The wife would likely be deeply hurt and angry, leading to the possible end of the marriage. There might also be a rift between the sisters.
Perhaps it has to do with a new and mysterious disease. In fanfiction, new and unique diseases can be created. This disease could be something that attacks his unique chakra system, which is different from others. Since his body is so reliant on chakra, if the disease disrupts it enough, it could lead to his death.
Perhaps in this fanfiction, on his birthday, Naruto is targeted by a powerful curse. This curse could be placed on him by a dark sorcerer who wants to end the hope that Naruto represents. As the day progresses, the curse slowly drains his chakra and eventually his life, while his friends are desperately trying to find a way to break it.