It could also be that Naruto sees in Boruto's eye a sign of an emerging danger. The eye might hold a clue to a new enemy or a brewing conflict. Naruto, being the experienced ninja he is, would then start to take precautions and train Boruto more intensively to face whatever this sign in his eye indicates.
The ending of the animated version of the Slaying Crimson Pupil TV series has not been announced yet because the work is still in production. According to the information we have, the work will probably be released in the next few years, so more details and endings may be revealed in the future.
It could be a rogue ninja who has a personal vendetta against Boruto's family. This ninja might have caused harm to Boruto's father Naruto in the past, and now Boruto is determined to make him pay.
It could be the Kara organization. They've been shown to be interested in Boruto's Karma mark in the original series, so they might have finally made a move to abduct him in the fanfic.
You can refer to the following storyline for the manga that transmigrated to kill the Crimson Pupil and become the god of the Empire:
The protagonist of the story was a modern man named Alan who accidentally transmigrated to an anime world called the "Scarlet Eye Empire". In this world, Alan found that the local gods had extraordinary abilities and the relationship between them was very complicated.
Alan began his adventure in this world. He needed to constantly face the challenges of various gods and work hard to maintain his identity and status in this world. In the process, Alan gradually understood the inner world of the gods and established friendship and trust with them.
In the end, Alan successfully became the god of the Scarlet Eye Empire and helped his people overcome various difficulties and challenges. In this process, Alan also continued to grow and improve to become a true leader and god.
In the novel "Taming the Heavens Begins from Slaying the Pupil," the protagonist used his golden finger to freely modify the ability to touch all attributes other than himself. He entered the world of Slaying the Crimson Pupil and could change all kinds of situations. After going through some tempering, he became a powerful minister. I hope you like this fairy's recommendation. Muah ~😗
The main people behind the Boruto manga are Ukyo Kodachi and Mikio Ikemoto. Their collaboration has resulted in an engaging and popular manga that expands on the Naruto universe.