Fill the Moon/Heartwarming

Considering Larxene of all people is a Grade-A Broken Bird and was absolutely Woobie-fied beyond all reason during the fic's run, it's not really a surprise that she and her lover get some of the best crowners.
- This troper's personal favorite is Lexaeus' Badass Boast. Not only does it count as a CMoA for Lexaeus, but it shows just how deep his love for Larxene runs, even without a heart.

"How much do you know?" She asked. Lexaeus didn't look away from her gaze as he sat down on the bed.
"How much do I know about what?" He replied. "I can tell you the thirty-seven different ways a man can find his way out of a labyrinth. I know how to construct a coliseum out of nothing more than the earth under my feet. I can tell you all about the behavioral patterns of the Heartless living on every single world that I know of as of now. I know how to converse in tongues forgotten by everyone except the trees and the land beneath my feet. I know how to survive the darkness that should warp and maim a human soul beyond repair. But I do not know what you wish for me to know." He told her.

- The best part about that, for this troper, is Larxene just had another rape-based Freak-Out and is panicking in front of Lexaeus. He manages to keep his cool, be totally awesome, and then pledge his love to her in like the expanse of two paragraphs!
Oh, they get plenty of these moments. Especially once they get, (finally), their relationship resolution. It's just adorable.
- They get another good one when he basically pledges himself to her. Not only is it sweet, it's total unadulterated badass.

Something in him seemed to spark and come alive, and he felt his body pulling him into a kneel. "Larxene, I swear upon my honor as an Apprentice to Ansem the Wise and a member of his guard, I will protect you until I can no longer stand the blows of your enemies." Lexaeus said, memories rushing back to him all at once-Radiant Garden, Braig-Even? Even, Ienzo?-home, Xeh, Dilan-teacher?-But it felt right. He needed to say those words again, and he needed to say them to her.
Larxene watched him with wide eyes for a moment. Her hands began to shake again, little wisps of lightning darting neatly across her fingertips. Lexaeus simply summoned Skysplitter, feeling it settle into his hands. He looked up at her and presented Skysplitter. "The Keyblade wielder will stand to fight. And thus, so will I." He murmured, his voice a quiet rumble. "And I will be fighting for your safety."

Marluxia gives Vexen his own greenhouse to make him smile. Even though the two of them are still stuck in relationship limbo at the time due to Vexen's Tsundere tendencies, Marluxia cares enough about Vexen to ensure his happiness.
- Not only that, but he gave him the greenhouse because Vexen had been complaining of being ill lately. Marluxia wanted to take care of him, d'aww.
- Plus, even though Vexen doesn't really like him at the moment, Marluxia made sure he could make the decision of whether or not to let him into his new garden. Vexen tells him that it's THEIRS, and that they should share it to make it worthwhile. Coming from Vexen, it's about the closest Marluxia gets to an "I love you" for like another hundred chapters...

After Vexen reveals that if they regain their hearts the placebo feelings--which, for the record, the Organization has been clinging to as their only way to feel affection for their loved ones--will disappear and seems far too cheerful about it, Xaldin's retort, tearing up his notes and telling him exactly how he's wrong and why is admittedly awesome. However, when he is comforted by Luxord and the two reaffirm their love for each other, it falls squarely into this trope.

"V-Vexen s-said I only w-wanted you b-because I didn't have a heart. Th-that I was settling." He said, pain and shock at his brother's betrayal making him stutter and choke on his words. Luxord didn't stop or change pace in his brush strokes; they remained slow and firm as Xaldin tried not to cry. "He thinks that just because he doesn't want to deal with Marluxia that the rest of us are just using our lovers because that's all we can get..." He shook his head.
"He's wrong, though! I didn't settle for you! I think I'm the luckiest man in the whole world for finding you, and no matter what happens, even if I get my heart back and lose it and get it back again a hundred times, I will always want to be with you! You and only you!" He snapped.
Luxord was still quiet, brushing his hair and letting Xaldin close his eyes and relax, the pleasure of being touched and pampered like a beloved kitten overwhelming him. He spent a few minutes in peace before he realized that Luxord still hadn't said a word, even after his outburst. He shifted in his position and looked up at his lover. "Luxord?" He whispered.
It took him a minute to realize it, but Luxord was crying. Xaldin had never, ever seen Luxord even so much as shed a single tear, but he was out and out silently sobbing. Xaldin sat up and hugged him tight, feeling Luxord's arms around him, keeping him safe and steady.
"That's all I needed to hear." He whispered, voice hoarse in Xaldin's ear. "Knowing you care is enough. Anything I say, my rose, would cheapen it."
Xaldin laughed. "I can think of one thing that wouldn't." He murmured. Luxord met his eyes and stroked his hair, shaking his head and sighing in amazement, feeling luckier and happier than he ever had, even when he could still feel the true emotion.
"I love you." He murmured. "And no matter what happens, that will always stand the test of time."

Despite the...issues...that Vexen and Marluxia have with their "relationship," so to speak, the two of them can occasionally get really, really cute Aw, Look -- They Really Do Love Each Other moments.

Vexen groaned, glaring in vain at the spot where Marluxia had once been standing. He would really have to discuss being "taken care of" by that damned man with him tomorrow...but the bed was warm, and he was tired, and Marluxia's hands had been so gentle...so very, painfully kind...
Vexen fell asleep with the feeling of warm, soothing hands caressing his cheek, and Marluxia's soft laugh ringing in his ears.

Basically, anything involving Axel and Roxas is guaranteed to run into this trope. For god's sake, they're soulmates before Roxas even EXISTS!
- To this troper, Axel's devotion to both Isa/Saix and Roxas is simply stunning. The two people who are most important in Axel's life are basically his life as a whole, and he would do anything for them. While Axel's limits haven't been tested with Roxas quite yet, Axel has come to blows with Xemnas on Saix's behalf, knowing he might die as a result, he spent what had to have been months searching the darkness for "his puppy," and he regularly openly defies Xemnas whenever he thinks he knows what Saix really wants and needs. While the author doesn't give him DILP treatment, he has some really awful breakdowns and can get violently possessive, overall, he just wants to help his friends and keep them safe, which brings more tears to this troper's eye than she would care to admit.
- As of the past two chapters, the hits just keep on coming. Axel still can't remember who Roxas is, but he still manages to confess his love, even if they haven't even met yet.

"He's mine. And he's beautiful. And no one will take him from me."

- Pff, that's nothing. According to Saix, Axel told Roxas that he loved him "more than there were stars in the sky." Considering that stars are on their way to becoming a huge symbolic motif for the two of them, that's saying something.
- Oh god, the entirety of chapter ninety. It's just...simply...beautiful. Absolutely divine, and shows the love between Roxas and Axel perfectly. To say any more would be major spoilers, but his love and adoration for that boy...is just...wonderful.
The entire "best friends forever" sequence in the very same chapter made this troper tear up. Considering what Saix and Axel went through in canon, watching them stay best friends is a great way to feel better if the general Bittersweet Endings of KH get you down.
As of the newest chapter, Axel has defected from the Organization just to find Roxas and be with him. If that isn't devotion, I don't know what is.
The Christmas special. Oh sweet baby Jesus, the Christmas special. This troper wept Manly Tears for an hour after that chapter.
- To wit; after Senayax and Zexion are revived, and the Organization receives their hearts, they return to Hollow Bastion and begin to live with the original restoration crew, along with Sora, Riku, Kairi, Namine, and Ansem. Considering the fact that Senayax is basically divided between two families, both of whom are at odds with each other due to what the Organization did to her--namely, getting her pregnant and almost killing her, seeing her confusion and sadness at everyone arguing is an initial Tear Jerker, sure... And then Ansem, (yes, that Ansem) dresses up as Santa. Which, in and of itself, is a cute moment. However, it's what he says to her that makes it bring tears of happiness.

"Do you think I can get what I really wanted?" She asked. Ansem didn't say a word; he just pointed towards the porch, where everyone stood waiting for her. Not a single person had argued or fought, and the only thing right then that mattered to them was the happiness she felt.
"You already have it." He replied.

- What makes this both sad and adorable is that she had already said all she wanted for her first Christmas was for her family to love each other. And seeing them all make amends brings a tear to this troper's eye...
The best part? Xemnas, due to his guilt over being the man who ordered Zexion to impregnate her, decides to give her a Christmas gift by himself. He gives her a picture of the Organization with her pasted into it, and glues a picture of the entire Hollow Bastion crew next to it. When Senayax starts to cry, so does the reader.
This troper admits it's a rather odd example, but the author has a side story called Relationship Developments, which, in her own terms is "just character development" in the form of, well, yaoi lemonfic. (She's being tongue in cheek, assumedly.) But it actually IS character development, and rather sweet at that.
- The best example of this would be the Xigbar and Demyx centric chapter. Demyx was abused by his older brother for his entire life, and so he has many, many scars. Xigbar has Vexen make some scar medicine for him, and even though Demyx is initially afraid that he's not going to be beautiful or good enough for Xigbar, he manages to summon up the courage to get rid of the scars and enjoy his new life with Xigbar. It's handled really well and is incredibly sweet, with its own crowning moment of funny in the fact that Peggy, Demyx's Empathic Weapon sitar...well, she likes to watch.
In the original story, in chapter three, there's a cute moment between Senayax and Zexion that starts off their relationship quite nicely. Basically, she gets lost outside the castle and he brings her home and snuggles with her in bed. Aww.
Oh, oh god, chapter four tastes like diabetes. It's just...aww. For starters, it brings the Velveteen Rabbit into the story as a huge motif; plus, come on, all of the Organization plus Senayax gathering together to read a bedtime story? Adorable.

"Will you read this to us, Zexion?" She asked politely. Zexion could only clasp the book and nod as he read the title. He winced. It was a child's book. In fact, it had been his book. But...it was what she wanted to hear.
He opened it to the first page as she settled into one of the plush chairs they kept for sitting and enjoying was so massive compared to her faery-like build that both Demyx and Saix could sit in it with her, and once she was settled, he began to read.
He let his voice and fingers guide him through the book. He didn't look up, didn't know if he could meet her eyes when he heard her soft sniffles upon learning the rabbit was to be thrown away. Because he hadn't looked up, had been so lost in the book, in trying to weave the words so tightly and so deftly she could truly believe the rabbit would be whole again, he never noticed when the other members of the Organization had all found their way here, surrounding the little girl as she huddled deep into herself and wished with all her might that the rabbit would be loved again.
He spoke the last magic words. He assured them all the rabbit was beautiful, safe, and loved. He described how the rabbit had become whole again, and as he finished the final page and shut the book, he suddenly noticed that he'd been crying. Senayax was crying as well, face buried between her knees and hood over her head as she tried to sob as quietly as possible. His whole body screamed at him to comfort her. He didn't know how. Couldn't remember how. Then finally, he found the words.
"We'll go into town tomorrow-every town in the whole universe, if we have to-and I promise I'll buy you a velveteen rabbit." He said softly. She nodded.
"Thank you..." She whispered quietly. Then, without warning, she threw herself at him and hugged him. "Thank you so much..."

- And this comes into play later, when Senayax finds out about Hollowmoon and she freaks out at the Organization and basically runs away. Zexion goes and buys her the rabbit, and, well, all is forgiven.
The rabbit shows up again a few chapters later, when she names the bunny. And as for what she names it...

"I'm gonna call him Ienzo." She announced.

In the next chapter, Xemnas announces that a few of the Organization are going back to Hollow Bastion to face the Keyblade Knight--namely, Xemnas himself, Xigbar, Marluxia, Larxene, and Lexaeus. Demyx gets a crowning moment of awesome when he flips out on Xemnas, but the heartwarming comes in when Xigbar tries to comfort him.

"Promise me, Demyx," he whispered, "please. Don't follow me. If you got hurt, I could never forgive myself either. Please, Demyx. I'm begging you." Demyx looked up at his one golden eye, and tilted his head.
"Xigbar..." He said softly, clutching the soft cloth of his shirt, "I can't promise that. I really can't. You're all I have." He said, desperately clinging to him and whimpering softly. Xigbar held him close.
"Demyx..." He whispered, his voice thick with pain and pleading. He shook his head. Xigbar could see tears glimmering on his eyelashes, and he stroked the tears away from his lover's almost painfully beautiful blue eyes, kissing him while Demyx shook in his arms.
"I...I promise not to...I..." He buried his face into Xigbar's chest again, tears starting to fall once more. "God, Xigbar, I can't...can't bear to think of you..." He sobbed. "Don't fade, please. Don't fade." He said, bordering on hysterical while he hugged him close. Xigbar nodded, wrapping his arms tightly around his little songbird.
"Promise." He whispered. Demyx could only nod, unable to say anything. Xigbar pulled him down on the bed and kissed him again. Demyx responded by winding his legs with Xigbar's, and the two clutched each other, staying entangled the entire night to protect each other from the darkness.

- Everyone else gets their little moments too. This troper personally likes Xemnas and Saix's best. I mean, aww.

"Ah, Saix. Feelings...mean nothing. But you...you are everything, are you not?" Xemnas whispered.

Larxene and Lexaeus get another cute one with puzzles. She finds him his puzzle piece, and it is just concentrated d'aww.