Tear Jerker / The Big O

• When Dorothy loses her sweet innocent pet kitten in episode 8, "Missing Cat". The kitten used to be a little boy.
  • The death of the kitten's real owners, who were actually his parents. They are brutally gunned down right before Roger who is outmatched and outgunned by their killer despite his best efforts. He makes clear he has no intention of negotiating with the man responsible once he finds him.
  • Then there's the kitten's ultimate fate. After having been transformed into a monstrous chimera, it finally finds the will to resist the man who made him this way on Dorothy's urging. When she pleads him to return home with her, he instead makes the conscious decision to die in the burning lab in which he was violently mutated, knowing he can never go back to his former life.
  • It has also been speculated that the rain that happens after Perro's suicide is supposed to represent Dorothy crying.
• The end of Episode 10 "Winter Night Phantom". Which has a pretty major one. Throughout the episode, Dastun has flashbacks to the movie he watched as a child, of the man who shoots the woman he loves at a pier. At one point, he even sees apparently the same woman holding a red balloon. At the climax of the episode, he confronts her at the pier in a real Generation Xerox moment, and re-enacts the final scene of the movie. Then at the very end, there is one final flashback of Dastun as a child watching the movie, with a young Sybil Rowan, who is holding a red balloon.
  • And toward the end of season 2, when reality itself seems to be falling to pieces, Dastun comes across a poster for the movie, advertising Dan Dastun as the male lead—and then he promptly runs into the child versions of Sybil and himself. Which means that, as a child, he watched a movie that he had already starred in as an adult, and then later plays out a real-life version of a scene from said movie with a woman who may or not have been the actress from the film. I don't think I've ever known something to be so tear jerky and mind screwy at the same time.
• Dastun's general sense of weakness and failure throughout Season 2. He's a Badass Normal in a world of Giant Robots, constantly witnessing the deaths of his men and his own powerlessness to protect the city. It culminates in his rebellion in the final episode where he can't even scratch the bad guy, and the troops who followed him are all wiped out.
• Kelly Fitzgerald weeping over her husband's body after he's killed by Alan Gabriel. She's shown gathering the broken pieces of his head into her hands, even as they spill out from her grasp.
• "Dorothy, since you've come to live here, I feel like I've known you forever."
• The ED "And Forever...".