Diarmuid Ua Duibhne



  • Class: Lancer
  • True Name: Diarmuid Ua Duibhne
  • Gender: Male
  • Source: Celtic Mythology, Knights of Fianna
  • Origin: Ireland
  • Alignment: Lawful Neutral
  • Height: 184 cm
  • Weight: 85 kg


  • Scenario writer: Nasu Kinoko · Urobuchi Gen
  • Original character designer: Takeuchi Takashi
  • Character designer: Mata
  • CV: Midorikawa Hikaru
  • Major appearances: Fate/Zero


Magical PowerD
Noble PhantasmB

Class Skills

Magic Resistance: [B]

Cancels spells with a chant below three verses.

Even being wounded by Greater Rituals and High-Thaumaturgy is difficult.

Personal Skills

Eye of the Mind (True): [C]

Perspective that has been cultivated through training and discipline.

Logic in battle to derive the possible means to survive in a predicament.

Love’s Beauty Spot: [C]

Charms the opposite gender through a beauty spot tinged with mana. The opposing females will bear a strong love towards him.

Avoidance is possible with the Magic Resistance skill.

Knight’s Strategy: [B]

A battle style that, regardless of power, induces a miss from the opponent while grasping the flow of battle. It’s not self-strengthening, but a skill that invites the opponent to fail a check. A composed observation ability to wager victory in an instant. Specifically speaking, it generates a lot of critical stars.

Noble Phantasm(s)

Gáe Dearg - Crimson rose of exorcism

  • Rank: B+
  • Type: Anti-Unit Noble Phantasm
  • Range: 2~4
  • Maximum number of targets: 1 person

Gáe Dearg.

The crimson long spear. Negates magical effects of the target touched by the blade.

Basically, a Noble Phantasm that has the ability to nullify magecraft defense.

Steals the magical effects from defensive equipment braided with magecraft like Saber’s armor, magecraft, or magecraft-like strengthening/skill boost by the Noble Phantasm 『A knight does not die with his hands empty』, and reduces them to a state of only physical defense.

The object of negating mana isn’t limited only to guards, but since it’s displayed 『only the part touched by the blade』 and 『only the moment in which the blade is touching』, it’s not suitable for defensive usage. Also, it can’t overthrow the effects of contracts or curses entwined in the past, as well as the effects of already completed magecraft. A spear that could be called a 『Noble Phantasm killer Noble Phantasm』, but this effect of exorcism alone can’t destroy Noble Phantasms. In the end, it negates the effects 『only the moment in which the blade is touching』.

Against those who don’t use magecraft, it’s a simple spear, but it’s unlikely not to use anything magical in a battle between fellow Servants, not flashy but a really useful Noble Phantasm.

Gáe Buidhe - Yellow rose of mortality

  • Rank: B+
  • Type: Anti-Unit Noble Phantasm
  • Range: 2~3
  • Maximum number of targets: 1 person

Gáe Buidhe.

The yellow short spear. Inflicts unhealable wounds. Impossible to dispel by normal means, wounds made by this spear won’t heal as long the spear isn’t destroyed or Diarmuid doesn’t die.

The mechanism through which any treatment or regeneration can’t be healed, is by making the damage dealt by the spear reduce the upper limit of the maximum HP. Therefore, even with treatment and regeneration, it won’t be healed further from that because the 『wounded state』 is the fully healed state.

Just a spear in decisive battles of brief duration, but thinking about the premise of fighting the same opponent multiple times over a long period of time, it’s like a body blow that works slow yet certainly.

If the target isn’t a Servant, a lethal effect like bleeding to death over time can be expected.

Same as 『Crimson rose of exorcism』, it lacks flashiness, but it’s an extremely easy to use Noble Phantasm. Incidentally, he who is the user won’t be hurt by this spear. Used as a set with Crimson rose of exorcism in FateGO.



  • First person pronoun: 俺 (ore)
  • Second person pronoun: 貴様 (kisama) / 〇〇 (without honorifics)
  • Third person pronoun: 貴様ら (kisamara) / 〇〇 (without honorifics)


Fervently loyal, a Heroic Spirit-like Heroic Spirit that esteems honorable battles.

In life, he broke the affection he received and betrayed his lord, and because of that his lord let him die without helping him, but he doesn’t regret his action of having chosen love over loyalty, nor grudges his lord for having let him die.

The story of his tragic love with the princess Gráinne, would later become the model for the story of Lancelot and Guinevere.

That nobility is hard to understand by others that aren’t the same type of person as him, and as a result of him having swallowed even that mistake, cracks will be more spread……

Despite having often met this kind of tragedies, his fundamentals never changed.

However, even for such a man, things have their limits. When confronting malice that doesn’t think about others, while his heart is burned by feelings of resentment, he has also spewed anger, laments, and curses.

Attitude Towards Master

There are no regrets in the conduct taken in life, or the destiny he chose.

However, if he’s given a second life, that time he’d choose and fight with loyalty……

A person who participates in the Holy Grail War with that kind of feelings.

Servants have, contract apart,『freedom to want the Holy Grail』, but in his case it’s not that he wants the Holy Grail, but that he aims to 『offer the Holy Grail to his lord』.

Thus, his conditions that are different from those of ordinary Servants, sometimes bring misunderstandings about his loyalty……

Dialogue Examples

『Who must win now is Saber? Lancer? Neither of them. What should win here, is the 「path of the knight」 that we serve ――― Isn’t that right? Heroic Spirit Artoria』

『My dearest wish of victory, I entrust it to the blade of the King of Knights. I leave it to you, Saber』

『I won’t kill my Master. I won’t kill Saber’s Master. She and I don’t wish to end things like this. Never forget it. If you survive now at this place, it’s for the nobility of the King of Knights』

Historical Character and Figure

A prominent warrior of the Knights of Fianna led by the hero of ancient Ireland, Fionn mac Cumhaill.

Appears in the group of mythological stories about the Knights of Fianna called the Fenian cycle. He had two spears called Gáe Dearg and Gáe Buidhe, and two swords called Moralltach and Beagalltach, and in his graceful face there was a magical spot given by a fairy that charmed women.

This spot, invited to and brought calamity. Having captivated Fionn’s fiancée Gráinne, he ended up eloping with her.

After wandering for several years, Diarmuid, who was allowed to return to the service of Fionn, who had finally calmed his anger, officially married Gráinne. But at one point, Diarmuid received a serious injury that left him moribund from a demonic boar while hunting. Diarmuid would have recovered if he had drank spring water scooped by Fionn’s healing hands, but Fionn intentionally or casually spilled the water twice, and Diarmuid died.

Character in FGO

In chapter 5 『North America Great War of Myths』, he appears in combination with who once was his lord, Fionn mac Cumhaill.

They serve as the Celtic faction’s advance-guard, but the delicate situation in which he receives sarcasm from Fionn with every little thing, no matter if he’s aware or not, perplexes the protagonist side. A master-servant relation with an odd tempo, but they were compatriots that matched their breathing.

Role in past works:

In 『Fate/Zero』, appears as the Servant of the prestigious mage Kayneth El-Melloi Archibald.
Perhaps a mischief of destiny, his Master’s fiancée Sola-Ui Nuada-Re Sophia-Ri becomes charmed by his magical spot, and as in the past, he ends up in the same composition of discord with the lord that ends up taking his life.

Fionn mac Cumhaill

Appear together as a knight’s Heroic Spirit, and fight together. Nothing can make him happier……!

Most importantly, Fionn-dono at his golden age is good! …… Well, those strange jokes at his golden age are troubling……

Cú Chulainn

Respects him as a great pioneer, and as a supreme spearman. But, isn’t that teacher too Spartan?

Comment from the Illustrator

Diarmuid was my favorite Servant since Zero so I was happy to draw him! But at the same time, I never regretted so much to be bad at drawing muscles. I went through Hell. I’m sorry. The clothing at the Ascension 3 Stage is very cool. This was suggested by Takeuchi-sensei. Knight clothing style. A ladykiller. (Mata)

Material Images