Persona 5 Royal Boss Guides: Every Showdown from Kamoshida to Maruki#

In Persona 5 Royal, story boss fights map one-to-one onto Palaces: every time the Phantom Thieves infiltrate a corrupt adult’s Palace, the run ends with a direct showdown against that ruler’s Shadow. This page gathers every story boss in infiltration order, the Reaper lurking in Mementos, and the showdown deadlines on the true ending route.

First, two official facts, so you don’t get misled by guides of questionable origin:

1. Atlus has never published per-phase move lists, exact HP values, drop rates or appearance rates for any boss. Claims like “phase one uses move X, phase two sits around Y HP” cannot be verified item by item in game, so this page carries none of them. Boss mechanics are only described up to what you can actually confirm in game.
2. Every boss’s weakness affinities can be confirmed in battle with the Analyze command. That’s why this page teaches “how to build a plan around weaknesses and extra turns” rather than a weakness cheat sheet you might misremember — covering your elemental bases thoroughly beats memorizing a table.

Main Story Bosses at a Glance#

The seven story Palaces each hold one ruler, and adding the Holy Grail at the bottom of Mementos plus Takuto Maruki in the third semester brings the story showdowns to nine. The first seven are mandatory — they are the only way to advance the story; the Holy Grail fight is just as mandatory; the Maruki fight appears only on the third semester route, and whether you enter it depends on Confidant conditions (see the showdown calendar below).

Shadow Kamoshida (Castle – Lust)#

Suguru Kamoshida ran the volleyball club as his personal fiefdom and ruled students through corporal punishment and threats, and his Palace is that urge to dominate given physical shape. As the first dungeon you fully infiltrate, this boss fight carries heavy tutorial duty: the complete loop of hitting weaknesses, knocking enemies down, 1MORE and the Baton Pass all prove their worth here for the first time.

Key strategies:

• Before attacking, make sure every party member has at least one way to hit an enemy weakness — the extra-turn advantage is the foundation of this fight.
• Morgana excels at healing and Wind attacks, and Ann Takamaki’s Fire attacks are already reliable during Palace exploration — let her handle damage while Morgana sustains the party.
• Boss fights leave far less room for error than fights against common Shadows: bring plenty of SP recovery items and build the habit of managing your healing chain from the very first Palace.

Shadow Madarame (Museum – Vanity)#

Ichiryusai Madarame styled himself a “master” while actually keeping his reputation afloat by plagiarizing his students’ paintings. Shadow Madarame shifts forms mid-fight and tries to inflict ailments on the party; from this fight onward, ailment-curing items deserve a permanent slot in your bag.

Key strategies:

• Yusuke Kitagawa joins the Phantom Thieves after the fight, putting an Ice attacker on the roster and noticeably improving elemental coverage for later Palaces.
• Against a boss that swaps forms, the rule is “re-confirm affinity reactions with Analyze after every form change” — don’t keep attacking based on impressions left over from the previous phase.
• The Museum Palace’s Shadows are largely art-themed, and plenty of negotiation rewards double as fusion material — no need to rush through the whole place underleveled.

Shadow Kaneshiro (Bank – Gluttony)#

Junya Kaneshiro got rich extorting students and lending money underground, and his Palace is a bank in the city center. The fight is built around the “giant vault plus the man himself” pairing: the vault form is hard to budge head-on, Kaneshiro himself is the real threat, and the cognitive ATMs that appear during the fight scramble your rhythm even further.

Key strategies:

• Don’t get drawn into extended fights with the ATM cognitions — take them apart when the chance appears and save your main turn resources for Kaneshiro.
• The fight against the boss himself trends long, so healing and SP management matter more than burst damage; Ryuji Sakamoto’s Electric attacks see wide use throughout this Palace.
• The areas and events unlocked afterward push the story toward summer — use the opening to catch up on Confidants and every later Palace gets much easier.

The Cognition of Wakaba Isshiki (Pyramid – Wrath)#

The fourth Palace belongs to Futaba Sakura herself — she walled herself inside a pyramid compacted from self-blame, and the guardian deep within is a cognitive image of her mother, Wakaba Isshiki. It’s one of the most unusual boss fights in the game: the Palace’s owner stands beside the battlefield, and the fight advances in step with her untangling her own emotional knot.

Key strategies:

• The guardian leans on powerful all-target attacks, so you’ll rely on the Guard command and your healing chain noticeably more than in earlier boss fights.
• The climax runs in sync with the awakening of Futaba’s Persona, and from this fight on her analysis and support skills become the team’s core backbone.
• The fight matters on the story level too: only after Futaba rejoins do the Phantom Thieves truly close the intelligence and support gap in their lineup.

Shadow Okumura (Space Station – Greed)#

Kunikazu Okumura is the conglomerate chairman who treats employees as consumables, and his Palace is a space station adrift in the cognitive world. The fight is famous for its relentless waves of robots under a turn limit — robots still standing when time runs out self-destruct together, putting the whole party’s survival on the line. Royal adjusted the timer and the difficulty, so the pressure is a bit gentler than in the original release, but it remains one of the least forgiving fights in the story.

Key strategies:

• The core of a wave fight is “who carries the Baton Pass into the next wave”: don’t burn all your SP and strongest skills within a single wave.
• Haru Okumura joins the Phantom Thieves in this chapter, adding Psy and Gun attacks to the roster; Makoto Niijima’s Nuclear attacks see broad use in this fight.
• Bring everyone to their best possible state before committing to the attack — this fight offers little room for trial and error; if you do get stuck, you can also lower the difficulty in game for a while (see the pre-battle checklist at the end).

Sae Niijima’s Palace (Casino – Envy)#

Prosecutor Sae Niijima’s Palace is the only one among the seven story Palaces that doesn’t end with a “Shadow showdown”: the climax is seeing through a rigged gamble and racing out of the casino with the classified data while the alarm blares — a timed escape fight. The pressure during infiltration comes from elite security and alert management, not from any single fixed boss encounter.

Key strategies:

• The watchword of the escape is “don’t linger in fights”: protect your SP and recovery items and spend every scrap of turn resources on reaching the exit.
• This chapter’s ending connects directly to the branching choice during Sae Niijima’s interrogation on November 20 — whether to sell out your comrades. One impulsive answer is Bad Ending 1, so save before you act.
• Makoto Niijima joined back in the previous chapter, and her Nuclear attacks plus well-balanced healing hold up across the entire Palace.

Shadow Shido (Cruise Ship – Pride)#

Masayoshi Shido is the politician openly campaigning to remake Japan, and his Palace is a luxury cruise liner. Shadow Shido swaps forms as the battle situation shifts, dragging his weaknesses along with them, which makes this the most mechanically intricate head-on showdown in the story. Royal adds a duel against Goro Akechi in the Palace’s engine room, and Akechi also fights alongside you as a playable party member.

Key strategies:

• Form switching means the weakness window never sits still: confirm affinity reactions with Analyze at the start of each phase, then decide on your main attacker.
• Keep one dedicated healer in the party (Makoto Niijima or Morgana) and configure the remaining slots’ damage around whatever form you’re currently facing.
• The story after Shido runs straight toward the Holy Grail at the bottom of Mementos — the December 24 showdown is close at hand, so make sure your save sits in a Safe Room once this fight is done.

The Holy Grail and Yaldabaoth (Deepest Depths of Mementos)#

On December 24, the Holy Grail at the deepest point of Mementos reveals its true face — Yaldabaoth, the false god who styles himself the God of Control and is called humanity’s natural enemy. This showdown consists of several chained fights whose resistances shift with each form, and it’s the largest head-on battle in the game.

Key strategies:

• Almighty attacks are unaffected by shifting resistances and stand as your ace damage tool in the endgame; until then, every phase still runs on the basic loop of “hit a weakness → knock down → 1MORE → Baton Pass”.
• Round out the elemental coverage of your Persona stock as fully as possible before the showdown: the deeper you go, the more the fight tests whether the protagonist can swap in the right mask for every resistance change.
• If Maruki’s Confidant hasn’t reached Rank 9 by November 17, the story wraps up in the original structure right after you beat Yaldabaoth, with no third semester and no true ending (see the showdown calendar for details).

Takuto Maruki and Adam Kadmon (Cognitive Science Institute – Melancholy)#

Royal’s true final boss. This showdown only appears once the Takuto Maruki (Councillor) Confidant reaches Rank 9 before November 17 and the third semester opens in turn. After you “reconfirm your resolve” on February 2, Maruki and Goro Akechi step fully on stage; Maruki’s Persona is Azathoth, which awakens into Adam Kadmon at the climax of the showdown. The final deadline for the Palace infiltration is February 3 — miss it and it’s an instant game over, time rewinds one week, and the true ending is void.

Key strategies:

• The fight plays out across multiple phases, and the endgame Adam Kadmon is as sturdy on defense as he is dangerous on offense; the steadiest approach is still to exploit weaknesses for extra turns, then stretch the damage advantage with Baton Pass and Technicals.
• Goro Akechi and Kasumi Yoshizawa are both usable party members in the third semester — get their condition and equipment in order before the showdown.
• This is the last battle in the game: a manual save beforehand, a tidied-up Persona stock and SP supplies are all non-negotiable.

The Reaper (Mementos Superboss)#

The Reaper is a super-tier superboss roaming Mementos, drifting along the paths on patrol, and a head-on encounter drops you straight into a high-pressure fight. Atlus has never published the floors it appears on or its appearance rate, so this page includes none of those numbers; the confirmable fact is that defeating the Reaper awards one silver trophy, and it’s an optional target — it affects no ending whatsoever and exists purely as a challenge for strong parties late in a playthrough.

Ground rules:

• If you don’t want the fight, don’t linger anywhere along its patrol route — detouring around it beats taking it head-on.
• When you decide to take the challenge, save manually first; its attacks can flatten an unprepared party within a turn or two.
• For the related Mementos mechanics and Jose’s stamp rally, see the Mementos page.

Weaknesses, Negotiation and Executions#

The underlying logic of boss fights breaks down into three pieces:

• Weaknesses and extra turns: landing a weakness knocks the enemy down and triggers 1MORE; knocking every enemy down opens a Hold Up and Negotiation. Against a boss itself, the point of weaknesses is seizing control of the turn order — every extra turn is one less volley you eat.
• Baton Pass and Technicals: the Baton Pass hands the turn between party members, and attacks get amplified with each pass; a Technical strikes an ailment-afflicted enemy with a matching attack type, raising damage to 1.5x. Which ailments pair with which attack types is detailed on the combat system page.
• Executions and your Persona stock: the Velvet Room offers five forms of execution — the Guillotine (fuses two Personas), the Group Guillotine (fuses three or more), the Gallows (sacrifices one Persona to strengthen another’s abilities), the Electric Chair (converts a Persona into an item), plus the limited-time emergency execution during a Fusion Alarm. Each form of execution corresponds to a trophy, and the elemental coverage of your fused Personas is exactly what backs “actually landing weaknesses” in boss fights. Obtaining a Persona through negotiation (rather than fusion) has its own dedicated trophy (I am Thou…).

Showdown Calendar: The True Ending’s Hard Deadlines#

Here is the most important mechanical fact in the game: the third semester and the true ending sit behind hard date gates, and missing one is irreversible.

The ending lineup in summary: there are 5 main endings in total — 3 bad endings, 1 normal ending and 1 true ending. The true ending requires refusing every bargain and clearing Takuto Maruki’s Palace by February 3; the Royal Ending is the true ending’s extended cut with one added scene (condition: Akechi’s Confidant at Rank 8), not a standalone sixth ending. One more caution: Kasumi Yoshizawa’s Confidant is not a requirement for the true ending — listing her as a true ending gate is a common misconception.

Pre-Battle Checklist#

• Manual saves: keep a separate backup save before entering any boss fight; on bad ending branch days (November 20, December 24, January 9), keep a dedicated save above all.
• Elemental coverage: keep at least one healing Persona and one support Persona on the protagonist, and fill the remaining slots against each Palace’s elemental blind spots; the later the boss fight, the more it leans on flexible Persona swapping.
• Ailment items: carry cures at all times — several boss fights sling ailments right back at you.
• SP supplies: boss fights generally run long; SP recovery items and your healer’s SP are the resources that most need protecting.
• Gear and resistances: pick armor and accessories against each Palace’s elements, and give skill accessories (drops from Royal’s Palace rulers) to your main damage dealers first.
• Difficulty: the game lets you adjust the difficulty at any time; at the start you choose from five tiers (Safety, Easy, Normal, Hard, Merciless), and lowering it while stuck costs you nothing in endings or trophy eligibility.

Boss Fights in New Game Plus#

There is no official “per-boss second-playthrough buff” mechanic of any kind; each Palace ruler is put together exactly as in the first run. Once a new playthrough inherits your money, gear and registered Persona compendium, the practical pressure of boss fights drops sharply; if you want a challenge, low-level clears on higher difficulties belong to challenge-run territory — see the dedicated challenge runs page.

Further Reading#

• Palace Guides — routes, gimmicks and Safe Room placement for all nine Palaces
• Combat System — the full mechanics of 1MORE, Baton Pass, Technicals and combo attacks
• Endings Guide — every ending branch and the dates the choices land on
• Mementos — Reaper encounters and the stamp rally
• Trophies — an overview of all 53 trophies and the Thieves Den achievements
• Walkthrough — the complete main story flow, day by day