Syd not only tells David that she rescued him because she loves him, but also affirms his place in the world and assures him that he is sane and that the rescue is really happening. Incredibly affecting.
Melanie also constantly reminds David and others that he is not insane, and that all he needs is help and companionship to be a healthy person.
Pretty much all of the David and Syd scene are too sweet for words, as the entire relationship is based in totally innocent first love. "A romance of the mind."
Special mention to episode 3 for focusing more on those two and less on David's brutalized mind. No less than two I love yous and an air kiss which is somehow just as romantic as any true kiss ever given.
Also when Syd travels into David's mind and shares a deep hug with young David is cute as can be since it's the only physical contact they've had since they swapped bodies over a year ago.
David's determination to rescue his sister. When he first finds out Division 3 has kidnapped her, he is fully willing and ready to go rescue her despite the fact that they almost killed him last time. Even when he locates her in astral form when the interrogators accuse her of knowing about David's powers and still sending him to a mental facility, he tells Melanie Bird the only thing he cares about is saving Amy.
The entirety of Chapter 4 is one big barrel of heartwarming.
Oliver's opening monologue to the camera, where he dismisses "violence as ignorance" and implores that children should be raised on empathy, rather than fear.
Cary and Kerry's relationship. There's no long or complex explanation needed. They take care of each other and what they have works for them.
The entire scene of David and Oliver chatting it up in the ice cube. Oliver offering to help David without even knowing him tells you right there what kind of person he is.
The whole episode is a monument to human expression and triumph over struggle via the dynamic of empathy vs fear. We see this in David and Syd's relationship with each other, in the contrasting philosophies of Kerry (id-like base desire to smash folks i.e. fear) and Ptonomy (non-violent, as befits his powers i.e. empathy), in the contrast between the battle-ready Kerry and the bookish Cary, in the therapeutic approach of Summerland vs the militaristic Division III, and finally in the growing war for David's mind between Oliver and the Shadow King. We as human beings constantly second-guess and belittle ourselves. Wear down self-esteem. Out of fear. And longing. Often, like David, we encounter persons and/or things that prey on those feelings. And we look to the people in our lives that, like Oliver, are there for support, want to help us figure things out, and get well again. Im rooting for you David Haller, because Im also rooting for myself and anyone out there thats ever felt lost or alone.
"They're watching." Philly risks her life to help her unstable ex-boyfriend.
The empowering way that Cary and Oliver dance as their allies are fighting the soldiers. It almost seems like a counter to the violence. Rebuking the fear provided by their enemies.
David straight up engages the Shadow King for the first time, starting the path that will eventually lead to his freedom.
David and Syd finally being able to touch each other in the Astral Plane.
David's experience in the Astral Plane classroom. His own mind helps him, step by step, realize that he's not sick and is under the sway of a powerful creature. Plus, the stunning reveal that Charles Xavier is his father in this universe, and gave him away to save him from the Shadow King.
It's incredibly touching how Oliver's attempt at protecting David and Syd from the bullets is a shield literally composed of the words "shield", over and over again. All while conducted to Ravel's Bolero using an olive pick. Beautiful.
This troper is also incredibly fond of how Oliver, after just returning to Summerland and having some severe gaps in his memory, immediately starts making everyone breakfast and ensuring that they feel right at home. What a good human being this man is.
The Interrogator revealed to have a loving husband and an adopted child, who support him and help in his recovery after nearly burning to death in the first episode.
David and Syd's goal to promote cooperation with Division III, instead of fighting them.
Syd's response to David coming back after a year.
David: "Can I kiss you?"
Syd: "You'd Better."
The compass David gives Syd. It always points to where he is so she'll never have to worry about losing him again.
The dynamic between Kerry and Cary seems to have improved to where they playfully banter like a married couple.
At first it's jarring to hear those familiar whispers surrounding David. Then, it's heartwarming to understand that he's finally in control of them. He's come so far.
The entire encounter with Future Syd. It's tinged with sadness, but also love. Terrific wordless acting by Rachel Keller. It's especially adorable how she draws him a heart with her light pen, and how she is noticeably still wearing the compass he gave her around her neck.
David meeting Future Syd again in Chapter 10. Despite her rough appearance and all she's been through, she gives a quiet nod when David asks if she wants to see him again.
David navigating the text game to rescue Melanie from her own mind in Chapter 11. He returns the sentiment she gave him in Chapter 10 in kind by reminding her of her love story with Oliver, and she not only snaps out of her maze but seems to have improved from her real-world funk as well. This is what he typed to set her free:
"Once upon a time there was a girl with no dreams. She lived in the right now. Then she met a boy and his dream became hers. Except what he didn't realize was she already had a dream. And that dream was to be carefree."
Chapter 12 has quite a bit of this:
Even though he's ultimately incorrect, and even though it's played for laughs, David telling Syd that he loves her no matter how bad she feels about herself or the awful things she had done in her life.
David being willing to relive Syd's memories of her awful childhood over and over again in order to help her get better and free her from her maze. He directly tells Child!Syd that he's never giving up on her. This entire season so far has had "pay it forward" moments like this where David has come to the rescue of the same folks who rescued him last season. It's incredibly affecting.
Syd's re-committal to her and David's relationship:
Sydney: Loves not going to save us. Loves what we have to save. God loves the sinners because our fire burns brightest. Burn with me.
The entirety of what happens in that final conversation is nothing short of incredible, real-life, relationship-building. Syd reaches a point where she's comfortable enough with her partner to reveal her scars and relate her past trauma. She's inviting him to know her. Fully.
Oliver seeing a vision of Melanie, while discussing morality with the Shadow King. Also doubles as a tearjerker.
Lenny thoughtlessly and selflessly comforting David after the latter finds out about his sister's murder.
The tender way that alternate timeline!Amy takes care of David when they're both quite elderly.
The stunning timeline where David is happily married with children.
The heartwarming montage at the end of Chapter 14 where David relives his own timeline from Clockworks on, and decides to stay where he is despite his massive grief for Amy. Implied that Syd is the catalyst. Set to an uplifting cover of The Clique's Superman from Hawley and Russo.
In Chapter 16, Farouk gently euthanizes The Driver after she shows him where his body is. It's oddly sweet, as the two seemed to know each other and were enemies at one point (she mentions The Professor by name). She wished for death and he granted it to her peacefully, like he was paying his respects.
Kerry and Cary talking about death surprisingly enough.
Kerry: I would stab death twice in the heart before he could get you.
Although they are hiding out from an apocalypse, Melanie and Oliver finally reuniting and getting to act like lovebirds in the ice cube.
While it has disastrous repercussions later on, when the time demons attack David's compound, Cary chooses to take Jiayi with him as he runs to safety.
After David erases Syd's mind and banishes her consciousness to the astral plain, leaving her child-like and helpless, Oliver and Melanie spend years raising her as their adopted daughter, rebuilding her personality so that she can reclaim her physical body.
Cary sacrifices his own health to restore Kerry. In return, she refuses to abandon him even though he's now weak and wheelchair-bound, taking him with her and Syd as they flee the airship.
The Grande Finale in general. Everybody, including David, get to do theirs lives over again. And it's all but guaranteed that they'll turn out pretty incredible.