One of the challenges for Gotham is that from the beginning, the audience knows where most of the characters end up and who they will become. The audience knows that Edward Nygma becomes the Riddler, that Selina Kyle becomes Catwoman, and of course, that Bruce Wayne becomes Batman.
Gotham navigates this challenge by putting a unique spin on each of these characters and making fans invested in the characters long before they become full-on superheroes and supervillains. The show prioritizes the journey over the destination. And, some of the characters' changes during these journeys can be embodied by their first and final lines in the series.
Butch Gilzean
"Hey, Oswald, you want a turn?" - "What?"
Butch's journey is heavily intertwined with Oswald Cobblepot. In his first lines, he offers Oswald the chance to hurt a man who is in debt to Fish Mooney. At this point, Butch is Fish's right-hand and Oswald is just her umbrella boy. Oswald seizes on the opportunity and gleefully hits the man with a baseball bat and Butch has to tell him to dial it back.
Butch spends much of his time throughout the show working for Oswald when he becomes a criminal kingpin. Butch's story ends in confusion as Oswald murders him, not because of anything Butch did, but because Butch's death is devastating for Tabitha Galavan. Oswald views it as retribution for Tabitha murdering his mother. Thus, Butch's story begins and ends with Oswald committing violent acts.
Alfred Pennyworth
"Alfred Pennyworth." - "Gave him hope."
Alfred's first and last lines are said to Jim Gordon and are related to the brutal murders of Thomas and Martha Wayne. Alfred's first words are when he introduces himself to Jim Gordon after coming to the alleyway to comfort a distraught Bruce and take him home.
In his last line, Alfred tells Jim that all those years ago in the alley, in the aftermath of the Wayne murders, Jim gave Bruce hope and provided him light in the darkness. Alfred makes it clear that Jim had a positive influence on Bruce, helping him find a way forward after experiencing unimaginable tragedy and trauma.
Lee Thompkins
"He's fine." - "I'm gonna cut this one."
Lee is a deeply comionate character. Her comion is part of what makes her such a good doctor and it is largely why she becomes Queen of the Narrows, as the people there respect everything she does for them. Lee's introduction is not so comionate, though, as Jim Gordon asks her if an Arkham Asylum patient is okay, and she responds by checking the patient's pulse, slapping him awake, and saying, "He's fine."
Her last line is in the series finale when she works on cutting the necessary wires to prevent a bomb from detonating. She initially cuts the wrong wire and barely has enough time to cut the correct one. Lee is the one to take on this task because of her steady doctor hands and she plays an integral in once again saving the day.
Barbara Kean
"And look at you and your excellent suit." - "You promise me."
Barbara's first and last lines are said to Jim Gordon. In her first line, she compliments him and his suit. She is a ive partner, but she doesn't yet know what she wants out of life.
Barbara in the series finale is a woman who knows who she is, what she wants, and has made a good life for herself. While she is no longer in a relationship with Jim Gordon, they did have a child together, and Barbara loves her dearly. Barbara's last line is a plea to Jim, making him promise that he will save their daughter from the Joker.
Harvey Bullock
"What the hell are you doing?" - "Who is he?"
Harvey's evolution as a character is encapsulated in his first and last lines. When fans first meet him, Harvey berates Jim Gordon for the way he handles a difficult situation within the GD Headquarters. Harvey is a cynic and he does not approve of Jim's idealistic and righteous approach.
Over the course of the show, Harvey becomes a more hopeful character and learns to stand up for what is right. When he asks who the Batman is at the end of the show, there is hope in his words, hope that this protector will bring true change to Gotham. This is the kind of hope Harvey did not have earlier in the show.
Edward Nygma
"Guess what this is." - "Tomorrow."
Even though he is not the Riddler yet when audiences first meet him, Edward Nygma already has a penchant for telling riddles. Instead of telling Harvey Bullock and Jim Gordon what he found in regards to the Waynes' murders, he tries to make them guess before revealing what kind of bullet was used by the killer.
By the series finale, he is very much entrenched in his Riddler persona. After being thwarted by Batman, though, his confidence is shaken and he is not prepared to move forward with his villainous schemes, and instead decides to put them off until tomorrow.
Oswald Cobblepot
"Sorry." - "Tomorrow?"
Oswald becomes one of Gotham's most ruthless and boldest characters, but his first and last lines are marked by fear. He is introduced as Fish Mooney's umbrella boy and utters a fearful apology when she lashes out at him for momentarily failing to shield her from the rain.
In his last line, Oswald suggests putting his villainous schemes on hold as he is scared to move forward with the Batman now protecting Gotham and thwarting criminals left and right.
Selina Kyle
"Pss-pss." - "Like hell."
Selina's connection to Bruce Wayne marks her first and last appearance in the show. After stealing some milk and a guy's wallet, she goes into an alleyway where she beckons a cat and offers it the milk she stole. The Catwoman foreshadowing is not lost on anyone, although the real significance of the scene is the setting as the alleyway becomes the place where she witnesses the savage Wayne murders. She is the only witness of the crime and the only person who understands what it was truly like for Bruce when his parents were gunned down beside him.
Her final scene is also with Bruce Wayne. He has returned to Gotham after a long absence. She tells him how much it hurt her a complex relationship that will only become more complicated as Bruce has returned to fight crime in Gotham and Selina uses crime to her advantage.
Bruce Wayne
"Sorry, Mom, I agree with Dad." - "Return the diamond."
The audience gets a brief glimpse of a happy, innocent Bruce Wayne talking with his parents about the show they just left. This ends seconds after Bruce says this line as his parents are ruthlessly murdered.
Bruce Wayne in the series finale is a hardened individual who has experienced unimaginable trauma and self-discovery. Instead of the frightened boy who Selina saw in the alley, he is now the confident vigilante protector of Gotham. His last line is in reference to Selina returning the diamond she stole, while his last appearance shows Jim Gordon, Harvey Bullock, and Alfred looking up at him in the full Batman costume.
Jim Gordon
"Hold your fire!" - "A friend."
When a criminal disarms a police officer and holds her at gunpoint in the GD Headquarters, Jim Gordon tells his fellow police officers to hold their fire and takes it upon himself to handle the situation in his own way. This is a Jim Gordon who believes he always knows best and that he always knows how to save the day.
The Jim Gordon in the series finale is wiser. He understands the value of allies and that saving the day can't be done alone. He gazes up at Bruce Wayne/Batman, calling him a friend, knowing he is someone that can be counted on to help save Gotham from itself.