The re-introduction of Kashin Koji in the Boruto Two Blue Vortex series might be one of the biggest game changers the authors might have introduced. The character not only brought this unique 'awakened' shinjutsu to the game, but his actions might also prove crucial for the future. However, his alliance with the protagonist might not last as long as the fans think.
The protagonist might have inherited Momoshiki's Future Sight through karma. As the activation of the karma might not be avoided at any cost, the protagonist might see the probable future which could be different than what Kashin Koji is telling. So, this might act as a breaking point between these two and could also unveil the secrets Kashin Koji might be hiding.
Disclaimer: This article contains potential spoilers from the manga and expresses the author's opinion.
Boruto: Why the alliance between the protagonist and Kashin Koji might end anytime

Boruto Naruto Next Generations marked the visible demise of Kashin Koji, one of the artificial beings created by Amado. The character was lost in a one-on-one showdown against Jigen (Isshiki Otsutsuki) and his whereabouts after this fight became unknown. However, given his mysterious death, fans were adamant that Koji would eventually return soon.
As expected, the character returned during the Boruto Two Blue Vortex when the protagonist was exiled from the Hidden Leaf Village. As described by Koji, during the last minutes of his fight against Isshiki Otsutsuki, he awakened his shinjutsu technique, the Ten Directions.

This technique helped him see different future timelines and enabled him to avoid any timeline of his choice. The character showcased his technique by mentioning various timelines, which allied Koji and the protagonist. However, the motives of Koji behind his alliance with the protagonist were unknown and this might soon lead to the eradication of this team-up.
Just like Kashin Koji, Momoshiki Otsutsuki had a similar power which the fans called Future Sight. This allowed the Otsutsuki to see the fate of any person, other than himself. After Momoshiki's defeat, he transferred his biological data inside the protagonist, hoping to be reborn as a new vessel. However, Momoshiki sometimes overtook the protagonist's body and showcased his innate abilities.

Logically, Boruto Uzumaki might eventually awaken Future Sight too, just like the other techniques he awakened. Moreover, even though the protagonist is trying his best to avoid the activation of his karma, this act might be inevitable given Kawaki's existence.
So, using Future Sight, the protagonist might witness the fate of his friends to realize that Kashin Koji might be leading to the death of some of them to ensure a safe future. This point in Boruto Two Blue Vortex might mark the end of this alliance forged to protect the Hidden Leaf Village.
Analysis and Final Thoughts
Every action that Kashin Koji might take, using Ten Directions, could be to assure his survival. As the protagonist is unaware of which actions might lead to which timeline, Kashin Koji might use his innocence to his advantage.
Given Koji's close-to-death experience with Jigen, he might have developed a phobia of death. So, his actions to assure his survival at the cost of others' lives might seem logical.
Related Links
- Making Boruto and Kashin Koji's relationship like Naruto and Jiraiya's would be the worst choice
- Kashin Koji could be hiding a heart-wrenching truth from Boruto
- Code vs Kashin Koji will be one of Boruto's most important fights