Tropes present in this episode include:
- Adaptation Distillation: The manga shows the entire coded conversation between Mustang and Hawkeye, whereas the episode cuts to Mustang decoding it after they mention Miles and Buccaneer.
- Armor-Piercing Response: When the homunculus remarks how the newly-named Hohenheim doesn't know how to read and write, the latter snaps that he's smart enough to do his work as is. In turn, the homunculus retorts "Your slave work", pointing out the folly of the young man's contentment with being a mere slave instead of bettering himself.
- Berserk Button: Slave 23's seems to be being called stupid, though he mellows out as he grows.
- The Caligula: The Emperor of Xerxes, judging by what he's willing to do to obtain immortality — though his subjects seem to view him as The Good King.
- Delayed "Oh, Crap!": When translating Hawkeye's coded message, Mustang is initially more focused on the decoding process than what the letters actually spell. It's only on the last two letters, when it's almost completely spelled out, that the message note and its implications hit him.
- Dramatic Irony: While thanking the Dwarf in the Flask for teaching him alchemy and helping him better himself, a young Van Hohenheim shares his personal hope of one day finding a wife and starting a family. There's something to be said for how he says this with such a content and hopeful inflection. Yes, he'll one day have his family, but it will be mitigated and short-lived, between his fear of outliving them and his 13-year mission to thwart Father.
- In the episode's stinger, Ed shares about how he's seen Philosopher's stones in different forms, but he's never seen one that truly held so many souls. As we cut to Hohenheim having dinner with the Curtis couple, we hear Ed monologue he would rather not see a giant Philosopher's stone if he can help it. Oh Ed, if only you knew you've not only seen one such Philosopher's stone before, but you were literally sired by him.
- Evil Cannot Comprehend Good: In a twisted way, the Homunculus (now Father) thought he was repaying Hohenheim the favor for giving him life by not only sparing him being made into a Philosopher Stone like everybody else in Xerxes, but also gifting him an immortal body via half the collective souls. Regardless, Father cannot grasp that Hohenheim is anything but happy, considering the survivor's guilt that comes with being a Soul Jar to half the lives taken from his country, including his friends.
- Eyecatch: Slave 23 and the Dwarf in the Flask.
- Fallen Hero: The King of Xerxes. It's implied that he really was once a good ruler, but in his old age has fallen victim to Immortality Immorality.
- Faux Affably Evil: Homunculus keeps himself chipper and witty even as he plans to sacrifice all of Xerxes and rope Slave 23 into it. It's all the more jarring to the audience who knows that Father, as he's presented in the present day, would not really act like this.
- The Good King: Subverted. It's implied that the King of Xerxes used to be this, but in his old age has become so desperate to avoid death that he's willing to sacrifice the lives of everybody else in the kingdom for the sake of becoming immortal. The implication he was previously a good king does explain why his subjects never suspected he was behind the raids.
- History Repeats: In fact, it mirrors how King Bradley is so beloved by the country that nobody even suspects he's a homunculus, much less that he's involved in a plot.
- Immortality Immorality: The King of Xerxes is so afraid of death that he has no qualms with sacrificing the population of his entire kingdom just to gain immortality. Homunculus ends up exploiting this to grant himself and an unwitting Hohenheim said immortality instead.
- Internal Reveal:
- Mustang learns via a coded message from Hawkeye that Selim Bradley is a homunculus.
- Izumi and Sig Curtis learn from Hohenheim that he is a living Philosopher's Stone.
- Like Father, Like Son: Young Hohenheim is revealed in this episode to have looked and acted a lot like Ed.
- Manipulative Bastard: Although the Emperor of Xerxes was the one who craved immortality, the homunculus was the one who played him into his game and used his thirst for immortality to ultimately betray him and steal souls for himself.
- Mirror Character: Awed at Young Hohenheim's refusal to learn in order to better himself, the homunculus wonders "Don't you even want freedom? Are you going to live out the rest of your life as a slave, without the rights of a real man?" To bring it home, he concludes "In that case, you're no different than me: trapped inside this stuffy flask."
- Public Secret Message: While having lunch with Mustang in the Central mess hall, Hawkeye conveys a coded message about Selim Bradley's true identity to him, under the guise of a chat about their mutual acquaintances.
- Small Role, Big Impact: Hohenheim's master and alchemy teacher is the one who created Homunculus, aka Father, from Hohenheim's blood, setting in stone the events that would come. The King of Xerxes in turn would demand the homunculus to tell him the secret to becoming the immortal, leading the homunculus to manipulate the king into creating a transmutation circle around the kingdom and sacrifice the entire population in order to turn himself and Hohenheim into living Philosopher's Stones, while also allowing Homunculus to create a body for himself that looks identical to Hohenheim.
- Skyward Scream: At the end, when Hohenheim learns he's become a Soul Jar.
- The Reveal: The episode reveals Hohenheim and Father's shared backstory and the reason why they look identical.
- Unwitting Pawn: Hohenheim/Slave 23 to the homunculus's plot.
- Wham Line: Homunculus decides to give Slave 23 a proper name, and the one they settle on sounds very familiar, to say the least.Homunculus: Well, how about Van...? Van Hohenheim. How does that sound?
- Whole Episode Flashback: To the last days of Xerxes.
- You Are Number 6: Number 23, in this case.
