The reason Lucy agrees to go along with the 100 Years Quest in the first place is because she believes she'll find Aquarius's new key in Guiltina, which Virgo heavily implies is where it is.
In the main series, Sorano swore that she wouldn't consider herself to be Yukino's Cool Big Sis again until she could finally atone for her misdeeds as a member of a dark guild. Now that she's been pardoned, Sorano hasn't simply reunited with her little sister; she's now a full-time member of Saber Tooth, where they're re-introduced embracing each other and gushing over how much they love each other.
In Chapters 12 and 13, Lucy has a total chance encounter with Brandish in the middle of the ocean, which is also their first meeting since the war with the Alvarez Empire. While Brandish appears miffed at first when she blames Fairy Tail for the Spriggan 12 disbanding, she quickly drops her anger and reveals she holds absolutely nothing against them—not even the death of August, her beloved grandfather figure, knowing full well that Fairy Tail's side suffered their own losses (particularly Mavis, if no one else). While Brandish typically declines to outright join forces with Fairy Tail, she and Lucy still part on friendly terms, which is particularly sweet since Brandish whole-heartedly believed they'd never see each other again the last time they met. Plus she secretly lends a helping hand anyway by beaching the enemy guild's ship for Fairy Tail.
Brandish revealing that Ajeel—who was already a Warrior Prince before his kingdom was absorbed by The Empire—abandoned his Blood Knight tendencies and became The Good King of Alvarez, with his beloved grandfather serving as his advisor. It goes to show that his talk with Elfman and Lisanna on the battlefield, as brief as it was, set him down the path to improving his life.
Erza reveals that Wendy helped create a Laser Blade form for her Benizakura sword so she could use Dragon Slayer magic. The new sword's name? Belserion, the self-chosen surname of her mother, Irene. What makes this significant is that Erza was bitter enemies with Irene right up until her mother chose to kill herself in an act of redemption and parental love, so the fact that the sword was christened after her indicates that Erza's opinion towards her mother has softened over the past year. Wendy's involvement in the sword's creation also implies that she has similarly warmed to her.
Gray goes on a "date" with an Identical Stranger to Juvia, during which we finally get a clear-cut answer about why there's been so much Unresolved Sexual Tension between him and Juvia, and addresses their Maybe Ever After at the end of the main series: he's a closeted Insecure Love Interest who doesn't feel like he's good enough to protect her, especially after her Disney Death in the war. With the look-alike's encouragement, though, he resolves to be more forward and self-confident around her from then on.
The first thing Natsu sees is his brother, Zeref, who reveals he's Happily Married with Mavis in the afterlife, and that they're raising a young August and Larcade—the former of whom died without telling his parents he was their son, while the latter, a demon Zeref more or less adopted as family, was cruelly disowned and killed during one of his "father's" fits of madness. Although it's indicated that this isn't really where they all went after they died, and that Zeref believes he's actually being punished in the afterlife for his crimes against humanity, it's all but stated that everyone here really is communing with Natsu and each other from the world beyond in some capacity. In other words, Zeref finally achieved his desire for happiness and a family with Mavis, something they never had in life.
When Igneel appears in Beta Heaven, he explains what Natsu's ideal version of Heaven truly is: a paradise where everyone he and his friends know who died—from family members like Lucy's parents and Atlas Flame, to friends such as Simon, Éclair, and Momon, and even foes such as Zirconis and (perhaps) Acnologia—can spend their afterlives in peace and happiness. Not only is Natsu reduced to a rare display of Tender Tears for them all, but it also demonstrates here more than anywhere else that this Hot-BloodedBlood Knight is, deep down, an All-Loving Hero who's capable of forgiving his most hated of adversaries.
Despite seemingly cutting all family ties with Zeref before his death and still showing apprehension around him in Beta Heaven, Natsu shows that he truly wishes his brother well in the afterlife, and has given him a special place within his own heart, even if Zeref is forever hated and condemned by everyone else who suffered and died because of him. Before leaving, Natsu calls Zeref "big brother" and tells him to look out for Mavis, proving that their family bond still holds.
As God Seed Aldoron and Natsu prepare to clash for real, Aldoron refers to Natsu as Ignia's brother. Natsu replies that while Igneel may be their dad, his only real brother is Zeref.
Several moments in Chapters 63 and 64, as it deals with the aftermath of Aldoron's defeat and Fairy Tail's freedom from their brainwashing.
Even the cover of Chapter 63 itself shows Lucy tearfully embracing Natsu upon finding him injured, but alive.
Juvia has one of her usual moments where she hugs Gray, but to everyone's surprise he returns her affection with a smile. It would seem he's finally getting comfortable with public affection displays.
Erza and Jellal have a moment outside where Jellal finally reaffirms he's done with his Death Seeker days and is now determined to live for the future, embracing Erza as he says it.
Gajeel thinks about the stories he and Levy will tell their future child. Is sweet to see them both so happy, considering their discussion in the first chapters.
Chapter 65 reveals that Edolas Natsu and Lucy, and Juvia and Gray got married and each had a kid, who Earthland Natsu and Gray quickly became attached to.
In Chapter 75, Aquarius returns, and though she does give Lucy a rather thorough chastising, she finishes it off by tightly embracing her, and appealing to the memories and identity Lucy suppressed after becoming a nure-onna. Eventually, Lucy can't hold it back, and bursts into tears, as Aquarius gently but firmly affirms her self-identity, before finally turning her back to normal (with, true to form, a sharp spank to the rear), much to Natsu's relief.
After Wendy inadvertently turns herself back to normal with her healing magic in Chapter 76, the first thing Natsu and Gray do is happily embrace her, overjoyed that she's back to normal.
Chapter 83: Thanks to the excess of magic on Elentir, Lucy can summon Celestial Spirits without the use of keys. This means, at least here, she can summon Aquarius one more time. And this time, she acts like a full-on partner in Lucy's plan to defeat Mimi.
Chapter 84 has Gray is put under a illusion where he's presented with a perfect, idyllic life, where not only are both Ur and Silver are alive, and Ultear is young, but where he's married to Juvia, and they have their own son. Even Gray can barely bring himself to cast off the illusion, but does it anyway, declaring that his goal is to make Juvia happy.
Chapter 100: Suzaku tells Natsu to join forces with him to stop Ignia from hurting their guild mates, saying that if he truly cares for them, he’ll do anything to keep them safe, including teaming up with a former enemy. Natsu promptly agrees to this.
Chapter 116: Kiria of all people shows that she has a heart very deep down by willingly assisting in the guild’s efforts to destroy the cores that contain Dogramag’s magic power. Why did she put her differences with them aside after all the times they’d humiliated her in the past? It’s because Suzaku is her friend and she’s not about to let him die. Laxus in particular is pleased to see that Kiria isn’t all bad, patting her on the head while adding that she has a really cute side to her, causing her to blush scarlet. She even shows concern for Selene when the latter exhausts herself from creating so many portals consecutively before having recovered from her injuries.
Chapter 154 reveals that Eric (formerly known as "Cobra") and Kinana are now engaged. When one considers just how far the two of them have come, and the ordeals both of them had to endure, the two finally finding happiness together is uplifting.
