Why didn’t Obito confront Kakashi after he witnessed him kill Rin?

Obito Uchiha's decision not to confront Kakashi after witnessing him kill Rin Nohara is rooted in a complex mix of emotions and motivations:

Belief in the Greater Cause: After Rin's death, Obito became more focused on his goals, particularly the idea of creating a world free of pain through the Infinite Tsukuyomi. He believed that confronting Kakashi would not change what happened and might distract him from his plans.

Overall, Obito's decision was a complex interplay of emotional trauma, ideological shifts, and a desire to pursue a larger goal, which overshadowed the personal confrontation with Kakashi.

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Shock and Trauma: Obito was devastated by Rin's death, which was a traumatic experience that left him in shock. The emotional turmoil he experienced might have prevented him from immediately confronting Kakashi, as he was grappling with overwhelming feelings of loss and betrayal.

Desire for Revenge: Obito's feelings of betrayal and anger were directed more towards the system that led to Rin's death rather than Kakashi himself. This shift in focus allowed him to channel his pain into a larger vendetta against the world.

Understanding Kakashi's Intentions: Obito understood that Kakashi did not kill Rin out of malice but rather as a result of the circumstances surrounding her death. Kakashi was trying to protect the village from the threat posed by Rin being a Jinchuriki. This understanding might have led Obito to feel conflicted about blaming Kakashi.

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Descent into Darkness: The event marked a turning point for Obito, pushing him further into darkness. Instead of confronting Kakashi, he chose to embrace his anger and grief, which ultimately led him down the path of becoming a villain.