It turns out that, far from being a happy-go-lucky idler, Avatar Kuruk spent his youth and damaged his physical, mental and spiritual health dealing with the mess left by Yangchen's favouritism towards humans over the needs of the spirit world, which meant he constantly has to battle with corrupted spirits who drained his life force and caused his early death. Yangchen is remembered as one of the greatest Avatars...while Kuruk, who gave his life helping to ensure that legacy, is remembered as merely mediocre, even by his friends and successor.
Kuruk really did value and love his friends and that love was shared among them as well during the journey's start; which makes revisiting Rise of Kyoshi that much harder, seeing that circle of friends at each other's throats by the time of the sequel. Compare Hei-Ran enjoying Jianzhu's company during Kuruk's flashback with her icy admittance that she would have killed Jianzhu without a second thought earlier in this book.
The narration of Kuruk's flashback refers to Hei-Ran, Jianzhu, and Kelsang drifting back to their own lives and ambitions as Kuruk losing "the treasures of his life." And his next life will witness it.
The chill of hearing Rangi coldly refer to the love of her life as "Avatar Kyoshi" hits deep and hard.
Yun bending away the portraits of the Fire Avatars in the royal gallery, to the point where Zoryu says it will be a blow the Nation will never recover from. Since we never get to see said portraits in the original showhe was right.
Hei-Ran cutting off her topknot, in what is a clear analogue to suicide in response to the fiasco at the Fire Nation party and also to make amends for her own part in turning Yun into the monster he has become.
"For faling to recognize the true Avatar. For not protecting my friend Kelsang. For letting my former pupil dishonor our nation. For not being worthy of my daughter's esteem."
When Kyoshi is reeling at Rangi nearly dying, which is bad enough, she is almost suffering Power Incontinence, as she admits if she opened her eyes she would destroy Yun but it wouldn't save Rangi.
While it was necessary since at this point Yun was too far gone Kyoshi and Rangi gain no satisfaction with his death and the two cry together in grief for their fallen friend. Kyoshi even wonders after Yun's funeral if there was nothing else she could have done.
When Kyoshi sees Yangchen while meditating, she is first disgusted, thinking it's her mother, before finally bursting into tears. Thankfully, Yangchen is nice enough to hug her, which reminds her ofKelsang, (Air nomad robes) compounding her grief.
