In Junpei’s battle, Mahito attempted to use the Idle Death Gamble technique on Yuji, but it had no effect. Therefore, we had to choose a different approach to confront the young man.

But why doesn’t Mahito‘s technique have any effect on Yuji?
1. When Yuji senses the impact of the technique, Mahito suspects that Yuji can understand the state of the soul because he has experienced being the vessel of Sukuna.
Initially, Mahito was confident in his combat skills, believing that even if he faced setbacks before attacking, the Idle Death Gamble technique would still work. However, he discovered an unexpected variable that prevented him from transferring his curse, which was Yuji.

At first, Mahito believed that Yuji’s combat ability was useless, but then he began to bleed. Mahito suspected that Yuji could perceive the soul state due to the shared essence with Sukuna. When he was confronted with the full force of Yuji, Mahito felt that the essence and spirit of his opponent were indeed being affected by the attack.
2. Sukuna – the powerful being within Yuji does not like Mahito’s technique touching the soul.
Besides the fact that Yuji can directly sense the soul state of Mahito, there is an external factor that prevents him from being affected by the Idle Death Gamble technique. That is Sukuna living within Yuji’s body. The King of Curses does not appreciate Mahito‘s technique touching the soul, so he has warned Mahito against such actions.

For Mahito, his strength compared to Sukuna is like land against the sky. Mahito once lost his mouth because he violated Sukuna’s warning about not touching the soul.
3. He will only be safe when Mahito uses his techniques while Sukuna does not intervene.
Knowing that Sukuna does not want his own soul to be touched, Mahito has already been warned by Sukuna immediately when activating his techniques during the battle with Yuji in Shibuya.

At the moment of initiating his techniques, Mahito encountered Sukuna in Yuji’s subconscious and mentioned that Yuji’s connection with Sukuna must be established to a certain extent. He should not let anything happen, so Sukuna advised him to just relax and watch.
Thus, Sukuna does not tolerate any form of interference that Mahito may have during his confrontation with Yuji. Hence, Mahito managed to escape Sukuna’s alert.