The Holy Grail is an enemy in Persona 5.
The holy cup of Jesus Christ, said to be blessed due to him drinking from it during the Last Supper. It is rumored bestow immortality upon those who drink from it along with other miracles. Galahad is sent by King Arthur to search for it in Arthurian myth. Dagda's Cauldron from Celtic myth is commonly associated with and mistaken for the Holy Grail.
The original form of Yaldabaoth that resides at the bottom of Mementos. A black metal cup filled with the blood red wishes of humans who desire to be enslaved to order and authority. The Phantom Thieves of Hearts fight the Grail on December 24th, but the constant flow of wishes for Yaldabaoth to take control of the world heal it faster than they can damage it, and turning it into a golden cup as the fight progresses.
Restored to glory the cup begins the plans for salvation upon humanity, tossing the Phantom Thieves back to reality as Mementos fuses with the earth and those with chaos are removed from it, coming very close to erasing both the Phantom Thieves and the Confidant from existence, only stopped at the last minute by Yuuki Mishima convincing his website that the Thieves actually exist and forcing Yaldabaoth to accept their continued being until he kills them the normal way. The thieves fight through the transformed Tokyo and his archangel heralds to fight it once again. A member severs the connection between him and humanity to allow him to be hurt, after which the cup transforms its body in a mechanical manner to become the angelic Yaldabaoth.
The first battle with the Holy Grail cannot be won - once damaged enough, it will regenerate with Will of the People. Keep attacking the Holy Grail to keep forcing it to heal, and each use of Will of the People will gradually change its colour, from its initial black to gold. When the Grail is gold, the battle ends prematurely as the party is ejected from Mementos.
For the second round, the battle begins with the Holy Grail once again demonstrating Will of the People. A Special Order then becomes available to cut its supply lines and disable that healing skill. Once this is done, it becomes a very straightforward battle. The Grail has no remarkable resistances or weaknesses, and has only Almighty attacks so it cannot hit weaknesses. The most dangerous attack is Eternal Light, telegraphed by its use of Gathering Light - put the entire party on the defensive to minimize the damage taken.
Once the Grail is defeated, the battle will progress to the final fight against Yaldabaoth.
- In Shin Megami Tensei IV, Dagda's Cauldron is mistaken for the Holy Grail by the angels.
- In the Japanese version, its unique skill "Eternal Light" (聖杯無尽光*)? shares the name with the unique race and skill of Kagutsuchi from Shin Megami Tensei III: Nocturne which are localized as "Light" (race title) and "Vast Light" (skill) in the English version.