However, Azulon was incensed at this lack of respect for Iroh's position and his loss and ordered Ozai to kill his own son, Prince Zuko, as an act of atonement.

Ozai ascended to the position of Fire Lord: although the events immediately following Azulon's secret murder are never depicted in flashbacks, it seems that his death was explained as the result of natural causes and that the still-mourning Iroh had no interest in challenging his brother for control of the nation, instead acquiescing to Ozai's investiture as Fire Lord and entering a permanent semi-retirement from state affairs.

When the story begins in Book One, Iroh is accompanying his nephew the banished Prince Zuko in his quest to capture the Avatar, a superhuman whose task to maintain world order makes him a threat to the Fire Nation's campaign of conquest.

Iroh is dismayed when Azula convinces her brother to betray them and is arrested while covering Aang and his friends' escape from the conquered city.

[8] In Book Three, held in a Fire Nation prison, Iroh fakes madness while preparing himself for the solar eclipse, during which Firebending does not work.

[11] In the series finale, Iroh has called the White Lotus to free Ba Sing Se from the Fire Nation—fulfilling his childhood vision, but as a liberator, not a conqueror.

In the episode "A New Spiritual Age", Iroh comes to the aid of Aang's successor as Avatar, Korra, who is trapped unprepared deep in the Spirit World.

Korra explains to Iroh that she is confused and doesn't know how to deal with the threat Zaheer poses to both the newly reformed Air Nation and the world.

In general, Iroh's inherent nature and the course of his life have brought him to a philosophy that embraces peacefulness, harmony, and mutual understanding rather than conflict.

In "Tales of Ba Sing Se", it is suggested that some of his perpetual optimism and generosity are a form of post-traumatic growth resulting from the death of his son Lu Ten.

[27] Reviewer Hayden Childs characterized Iroh's vignette as "a lovely piece of storytelling" and praised Mako's "amazing performance" in the character's short story.

He praised Mako's performance in voicing the character, while characterizing Ozai stealing Iroh's birthright as the next Fire Lord as "almost Shakespearean".

[29] Reviewer Keval Shah termed the scene where Iroh sacrifices himself to allow Aang and Katara to escape Azula in the season two finale, "The Crossroads of Destiny", as "emotional".

[31] Iroh's introduction into the series was observed as a plot device to help Korra, who at that point was a somewhat unpopular character among fans and critics alike, become a more likeable protagonist.

[33] Iroh also appears in the video game Avatar: The Last Airbender – The Burning Earth, as a character in both the main story, and in multiplayer mode.