Anti-Climax Boss: In-Universe example. The final Guardian of Tartarus goes down like a chump, slightly disappointing Roy.
Arch-Enemy: Of all Roy's enemies, Jin seems to be the one he hates the most. Unless one includes Ryoji/Nyx on that list.
Arson, Murder, and Jaywalking: After getting beaten horribly by Roy and then acting as Mr. Exposition, Ryoji falls asleep on the bridge. His last conscious thought is that he hopes his nose doesn't get broken from the fall.
Ascended Extra: Hamuko Arisato (the female P3 MC) acts as a recurrent side character.... until she joins SEES.
The Reaper is treated as a character and reoccurs throughout the story.
Roy and Shade team up against a third version of Roy inside a casino inside of Roy's head at one point.
Berserk Button: Don't ever try to kill his friends (least of all, Aigis). Or damage his hat. Do not discuss his dead parents, especially not in front of other people. Don't take your marital problems out on your child. Lastly, don't lie about him, least of all to his face.
Hair-Trigger Temper: Not only does he have a few buttons, but even accidental pressing will set Roy off.
Big Damn Heroes: The Reaper pulls this off thrice. First he frees Roy from Ikutsuki's trap, then he keeps Takaya from attacking the group during an encounter with him. Then once more during the final battle.
Koromaru also helps with the first instance of the above.
Hoist by His Own Petard: Lampshaded, of course, by Roy. Who set Roy up so that he could take down Ikutsuki? Koromaru, the very dog Ikutsuki insisted on adding to the team.
Ice-Cream Koan: Roy's comforting words to "Maya", openly admitted by the narration.
Inner Monologue: Considering that the readers are taking a peek into Roy's head, a lot of this is to be expected. If you combine this with Shade's or Azren's banter, it becomes something like an Inner Dialogue.
The Other Darrin: Allegedly played straight, though not really a trope that can come into play during a fan fiction. In Chapter 46, Roy's voice starts sounding like Dante because the author got tired of imagining him speaking in a different voice.
Person As Verb: Azren talking to Roy about the possibility of Chidori sacrificing herself to save Junpei's life by "pulling an Edward Elric". The best part is that Junpei and Edward are both voiced by Vic Mignogna.
The Power of Rock/Autobots, Rock Out!: How SEES ultimately combats the Hermit, or at least what helps set the mood. The best part is that Elizabeth, Theodore, and Margaret play Through The Fire And Flames for background music.
Mutual Kill: How Mitsuru and Chidori defeat each other in the coliseum.
No Holds Barred Beat Down: Hades unto Yukari, in a very similar way to the one in A Fool Named Fortune. The victim even pressed the same Berserk Button. Further proof that it's Roy's worst button when it's revealed Hades is a part of Roy.
Only Sane Man: Hades acts as this, especially when SEES about to start fighting over the keys. At that specific time, Shinjiro, Hamuko, and Koromaru adopt this behavior as well and take his side. Junpei has this trope in the same way he did in the original version of The Answer.
Many character tropes for Roy still apply, though should be re-listed if they are used differently.
Adaptation Expansion: This version further takes a look at Roy having a new life in Japan, specifically how he's left behind a few of his friends in Seattle and talks to them at one point, as well as his physical fighting abilities.
Bare-Fisted Monk: Roy's Weapon of Choice is gauntlets once again. Unlike last time, he uses them right from the first battle, not to mention his Mixed Martial Arts.
Barrier Change Boss: Exaggerated with the Emperor and Empress once they Turn Red - They start changing weaknesses far too fast for the party (Fuuka included) to react accordingly.
Big Damn Heroes: Hamuko helps the party against the Priestess Shadow when things are looking grim.
Referenced to before the Hierophant and Lovers Shadow fights.
Big Eater: Hamuko Arisato is one, right from the beginning this time.
Blessed with Suck: Roy often remarks that being a Wild Card means "[he] can't even be weird in a normal way."
Chapter 12 has some Call Forwards, unexpected Call Backs, and a very unexpected Mythology Gag. In order: Roy literally runs into Yosuke after getting Aigis clothes. He then gets put through Training from Hell by Lisa Silverman, who is dating Tatsuya Suou. He meets the Hito-Shura when Koromaru awakened Cerberus. After arriving in Inaba, Roy name-drops St. Hermelin, Seven Sisters and Kasugayama as competing schools. While searching for his uncle's shop, Roy gets run over by the dog that Chie raised for Yukiko and meets Chie, and unexpectedly shakes hands with Izanami. Finally, he watches Kanji beat the shit out of the bikers, and subsequently meets Dojima. What a mouthful...
Chapter 17 brings a bigger... crossover(?) ...to the table: Shinjiro has an aunt, uncle, and little cousin. His aunt and uncle are Argilla and Roland (although Argilla is renamed Asami).
On another note, a small note made by Roy calls Yukari (to quote): "the biggest closet Featherman nerd this side of Ken Amada and nothing you say or do will convince me otherwise". This is due to the author's headcanon that Yukari is the biggest nerd in the group due to her appearance in the Persona 4 Arena sequel.
Genre Savvy: Roy doesn't have this as much as last time, but he knows enough about certain genres to convince Junpei that being the hero's best friend is better than being the hero. During the monorail operation, he claims that the hero's friend usually gets a better-looking girl who may or may not be swayed from evil.
Hidden Depths: Junpei is quite knowledgeable about coffee, just like in the FeMC's link with him.
Let's Get Dangerous/I Am Not Left-Handed: Roy wears a sarashi on his arm until he decides to get serious in a fight and start going all out. He's able to succeed at fights splendidly without doing this, for the most part.
Memetic Molester: In-Universe. This time it's not just Roy who finds Ikutsuki to be unsettling.
Mood Whiplash: Roy mentions this trope when he establishes the Devil Social Link with Ken in Chapter 13.
"No, Roy, you just don't get it." I said. "One does not simply LIKE Doritos, one fucking LOVES Doritos because they are what is right and just in the world! If you don't like Doritos, then the terrorists WIN!"