I heard about this Book 4 and saw your post with links. I don`t know English very well and I have a feeling that there are a lot of text. Can you please recap all main ideas for it if this won`t bother you?
Yeah, I can do that. These are all of the main ideas:
There was going to be a two-part flashback episode about Iroh’s transformation into the person he is today. It would feature the siege of Ba Sing Se, Lu Ten’s death, and his travels around both the mortal and Spirit World.
Toph learns to heal from the emotional abuse she endured from her parents and repairs their relationship. She would receive character development to mellow out her harsh personality. Katara’s motherly influence helped her, but Toph needed to deal with the direct cause.
Katara never ended up with Aang at the end of ATLA, and Mai never went back to Zuko. Katara was going to express concern for Zuko being torn between his duties as Fire Lord and his desire to search for his mother.
The Southern Water Tribe experienced the longest series of attacks from the Fire Nation. Zuko and Katara become political partners and work together to help end the animosity and repair relations between their two nations. Just like how Zuko learned to appreciate the Earth Kingdom, he would learn to appreciate the Water Tribes. Katara also learns to respect the complexity of Fire Nation culture. There is no such thing as an “evil” nation.
Zuko was going to admit that nobody understood him like Katara did, and how he was grateful to have met her. Katara was going to say she felt the same way about him. Neither Aang nor Mai could understand Katara and Zuko like they did with each other. Katara and Zuko begin to develop feelings for each other as they spend more time together but they attempt to deny this.
Aang would start to suspect something but would tell himself he was just imaging things. Aang would then leave on a self-searching journey after feeling the consequences of energybending and getting jealous over how close Zuko and Katara had become. Both Zuko and Katara would be very confused about this situation since Aang is their good friend. They don’t want to hurt his feelings, but their bond is continually strengthening as well, without them even realizing.
As a consequence for choosing not to take Ozai’s life - a darkness would start to bloom within Aang, stemming from the guilt of taking away the his bending; which broke the former Fire Lord’s will to live. Energybending is a dangerous art and has the power to corrupt the user. Aang needed to go on a journey to rediscover himself, this leads him to split up from the rest of Team Avatar and head towards the Air Temples again.
There he learns about powerful airbending techniques and makes important discoveries about the history of his people. During Aang’s disappearance, Zuko and Katara would grow closer. Aang loves Katara but not in the way he should, as it was based on replacing the absence of the Air Nomads, and Guru Pathik believes he never learned what it meant to “let go” of her. Aang and Katara are not on the same wavelength as there are many times where Katara attempts to shelter him from the harsh realities of life - which creates a chasm between them.Katara discovers she can communicate so much more easily with Zuko, and he with her.
An episode about Aang’s parents, with his mother being pregnant, and later giving birth. Avatar Roku dies approx. a week before Aang’s birth so the Air Nomads are looking for the next Avatar and they identity Aang as it. He spends a very short time with his parents before he is taken away to be raised in the Southern Air Temple and is too young to remember anything about them.
Aang finds out that some of his people were alive all along and just hiding; living their lives for the past hundred years without him. His love for Katara grew from the love of the Air Nomads, so what if his people came back? Would he realize that his love for her was not as genuine as he once thought?
