However, there are several episodes where he faces challenges and struggles that make him question his beliefs or lose control temporarily.
Here are a couple of episodes you might be thinking of:
* Season 1, Episode 48: "The Enemy Within": Judai confronts Zane Truesdale, a former friend who has been corrupted by the power of the "Supreme King" and his "Elemental HERO Neos". Judai struggles with his own inner darkness as he fights to save Zane from the "Supreme King's" influence.
* Season 3, Episode 127: "Judai's Shadow": During a duel against the "Supreme King", Judai's spirit is momentarily taken over by the "Supreme King's" dark power. He loses control and attacks his friends, revealing a darker side to his personality. However, he regains control and defeats the "Supreme King" in the end.
It's worth noting that Judai's struggles are always ultimately rooted in his desire to protect his friends and fight for what he believes in. He never truly embraces the darkness, but uses it as a stepping stone to become stronger and more resilient.