Bryn2 This Servant is a Limited Servant Limited. It is only available during special summoning campaigns. When no such campaigns are active, this Servant cannot be summoned. No plans have been revealed to add this Servant to the permanent summoning pool.

This article is for Class-Berserker-Gold Mysterious Heroine X. For 5★ Class-Assassin-Gold, see Mysterious Heroine X. For 4★ Class-Foreigner-Gold see Mysterious Heroine XX.

Servant DialogueInterludeStrengthen


Mysterious Heroine X (Alter)

★ ★ ★ ★ ★

Japanese Name: 謎のヒロインX〔オルタ〕
AKA: MHX Alter, MHXA, Ecchan
ID: 155 Cost: 16
ATK: 1,717 / 11,113 HP: 2,079 / 14,175
Grail ATK: 12,165 Grail HP: 15,529
Voice Actor: Kawasumi Ayako Illustrator: BUNBUN
Attribute: Star Growth Curve: Semi S
Critabsup Star Absorption: 9 Stargainup Star Generation: 5%
Npchargeup NP Charge ATK: 1.07% NPGainUpDmg NP Charge DEF: 5%
Instapowerup Death Rate: 37.3% Alignments: Neutral・Evil
Gender: Female
Traits: Arthur, Dragon, Female, Humanoid, King, Saberface, Servant
Quickicon3  |  Artsicon2  |  Bustericon4  |  Extraicon5
Active Skills Passive Skills Noble Phantasm Ascension Skill Upgrade
Bond Level Biography Availability Trivia Images

Active Skills

Available from the start
∞ Black Bean Paste EX
Increases own healing received for 3 turns.
Recovers own HP.
Level 12345678910
Healpowup Heal Rate + 20% 23% 26% 29% 32% 35% 38% 41% 44% 50%
HealEffect Heal + 1000 1100 1200 1300 1400 1500 1600 1700 1800 2000
Cooldown 7 65

Upgrades after Interlude, Replaces ∞ Black Bean Paste EX
∞ Chestnut Paste EX
Increases own healing received for 3 turns.
Recovers own HP.
Hpregen Recovers own HP by 1000 every turn for 3 turns. UpgradeIconText
Increases own critical damage of Quick Cards for 1 attack, 3 turns. UpgradeIconText
Increases own critical damage of Arts Cards for 1 attack, 3 turns. UpgradeIconText
Increases own critical damage of Buster Cards for 1 attack, 3 turns. UpgradeIconText
Level 12345678910
Healpowup Heal Rate + 20% 23% 26% 29% 32% 35% 38% 41% 44% 50%
HealEffect Heal + 1000 1100 1200 1300 1400 1500 1600 1700 1800 2000
Critdmgup Quick Crit Damage + 20% 21% 22% 23% 24% 25% 26% 27% 28% 30%
Critdmgup Arts Crit Damage + 20% 21% 22% 23% 24% 25% 26% 27% 28% 30%
Critdmgup Buster Crit Damage + 20% 21% 22% 23% 24% 25% 26% 27% 28% 30%
Cooldown 7 65

Unlocks after 1st Ascension
Instinct C
Gains critical stars.
Level 12345678910
GainStars Stars + 4 5 6 7 8 9 10 11 12 14
Cooldown 7 65

Upgrades after Strengthen, Replaces Instinct C
Instantaneous Shadowless Blade C+
Increases own Quick performance for 3 turns. UpgradeIconText
Gains critical stars. UpgradeIconText
Level 12345678910
Quickupstatus Quick + 20% 21% 22% 23% 24% 25% 26% 27% 28% 30%
GainStars Stars + 10 11 12 13 14 15 16 17 18 20
Cooldown 7 65

Unlocks after 3rd Ascension
Sovereign's Invisible Hand C
Starabsoprtdown Reduces one ally's critical star absorption by 100% for 1 turn.
Increases party's attack for 3 turns.
Level 12345678910
Attackup Attack + 10% 11% 12% 13% 14% 15% 16% 17% 18% 20%
Cooldown 7 65

Passive Skills

Mad Enhancement C
Increases own Buster performance by 6%.
Altreactor A
Increases own debuff resistance by 20%.

Noble Phantasm

Black Dragon Twinblade of Victory
Rank Classification Type Hit-Count
A+ Anti-Unit Quick 9
Effect Deals damage to one enemy.
NP Level 1 2 3 4 5
Powerup Damage + 1200% 1600% 1800% 1900% 2000%
Overcharge Effect Deals extra damage to Class-Saber-Gold Saber class servant.
Charge 100% 200% 300% 400% 500%
Powerup Extra Damage + 150% 162.5% 175% 187.5% 200%

謎のヒロインX〔オルタ〕 黒竜双剋勝利剣

謎のヒロインX〔オルタ〕 黒竜双剋勝利剣


Item 1 Item 2 Item 3 Item 4 QP
1st Berserker piece5 Qp100,000
2nd Berserker piece12 Dragon fang18 Qp300,000
3rd Berserker monument5 Medal of Great Knight20 Primordial Lanugo3 Qp1,000,000
4th Berserker monument12 Primordial Lanugo6 Dragons reverse scale5 Qp3,000,000

Skill Reinforcement

Item 1 Item 2 Item 3 Item 4 QP
1st Shiningberserker5 Qp200,000
2nd Shiningberserker12 Qp400,000
3rd Magicberserker5 Qp1,200,000
4th Magicberserker12 Medal of Great Knight10 Qp1,600,000
5th Secretberserker5 Medal of Great Knight20 Qp4,000,000
6th Secretberserker12 Dragon fang12 Qp5,000,000
7th Dragon fang24 Blacktallow4 Qp10,000,000
8th Blacktallow11 Cursed Beast Cholecyst10 Qp12,000,000
9th Crystallized lore1 Qp20,000,000


Strength: A
Endurance: B
Agility: B
Mana: A+
Luck: C
NP: A++

Bond Level

Bond Level 1 BoundLevel1 2 BoundLevel2 3 BoundLevel3 4 BoundLevel4 5 BoundLevel5 6 BoundLevel6 7 BoundLevel7 8 BoundLevel8 9 BoundLevel9 10 BoundLevel10
Bond Required 2,000 3,000 4,000 5,000 6,000 230,000 250,000 300,000 380,000 438,000
Total Bond 2,000 5,000 9,000 14,000 20,000 250,000 500,000 800,000 1,180,000 1,618,000
Bond 10 Reward 429icon Dark Knight-Kun
When equipped on Mysterious Heroine X (Alter),
Increases Party’s damage to Saber class enemies by 20% while she is on the field.
Chaldean Visionary Flames [?]
11 BoundLevel1 12 BoundLevel2 13 BoundLevel3 14 BoundLevel4 15 BoundLevel5
1,090,000 1,230,000 1,360,000 1,500,000 1,640,000
2,708,000 3,938,000 5,298,000 6,798,000 8,438,000


Unlock Description Translation
Default サーヴァントユニヴァースより来訪した天涯孤独のヴィラン(悪役)。



A Villain (antagonist), the last of her kind, on a visit from the Servant Universe.

A hard-to-come-by literary Berserker.
An Anti-Anti-Saber final weapon who swears to defeat Mysterious Heroine X whilst fuelling her magical energy converter, the Altreactor.

You don't know what's going on anymore, you say?
---Don't think. Feel.

Bond 1 没落の騎士ペンドラゴン卿

属性:中立・悪  性別:女性

Fallen Knight Sir Pendragon

Height/Weight: 154 cm / 42 kg
Source: 2017 Valentine's Event
Region: Servant World
Alignment: Neutral・Evil

Gender: Female
Her prided sword, ‘Wicked Holy Sword Necrocalibur’, was bought online from a shady vendor.

Bond 2 「闘うよ。ヒロインXを倒し、



‘I'll fight. Until the day I defeat Heroine X,

and stain the universe with the darkness of villainy.’

The voroid ‘K6-X4’—a.k.a. ‘Black Knight-kun’—is always watching over the girl and her oath from the shadows.
In other words, he's hiding away and being lazy on a whim.

Bond 3 まじめでひかえめな態度の少女。



A serious and reticent young girl.

Has a sweet tooth. If you give her the chance, she'll request luxury Japanese sweets.
A relatively costly glutton.
On days off, she doesn't take a single step away from the Black Round Table-type kotatsu.

There, she spends her day reading books and listening to music.
She's basically a slob who can't be bothered.
Curiously, she will follow orders and instructions, obedient in her own way, albeit served with a side of sarcastic retorts.
Bait her with sweets to get her going.

Bond 4 魔力転換炉オルトリアクターは、体内に秘めるオルタニウム結晶を触媒として、カロリーを魔力へ変換する。



The magical energy converter, the Altreactor, converts calories into magical energy, the Alternium crystals hidden in her body acting as a catalyst.

‘The component balance of wasanbon sugar is the most effective. Also, I'll have some green tea,’ she emphasizes.
Spectacles are a necessary item to rest her boosted optic nerves. In fact, her eyesight deteriorates when putting them on.

The mysterious item in her possession, the ‘∞ (Infinity) Black Bean Paste’, was made through the six fundamental forces of
Desire (Soul), Sugar (Power),
Sales Location (Space), Cost Price (Reality),
Production (Time), and Demand (Mind).
Although said to grant infinite power to its wielder, X Alter doesn't really have a clue.

Bond 5 すでに壊滅し失われた暗黒の騎士団ダーク・ラウンズに連なる最後の生き残り。



The last survivor of an annihilated and lost order of dark knights, the Dark Rounds.

The title bestowed on her is Sir Pendragon.

She employs a variety of strangely familiar techniques such as the psychokinetic "Alter Choke" and the ultimate technique ‘Alter Lightning’, which releases magical energy from the forearms.
Emitting crimson magical energy, the ‘Wicked Holy Sword Necrocalibur’ can be transformed into a twinblade or chainsaw at will, but frequently breaks and blows up.
It seems to be a universal law
that cool weapons aren't very powerful.
All said and done, nothing beats the standard longsword.

Clear Interlude
Extra 「謎のヒロインX」から抽出されたX因子を元に、禁断の魔術によって錬成された人造サーヴァント。


An artificial Servant created by forbidden magic, based on the X factor extracted from Mysterious Heroine X.

Eventhough it tries to eliminate Heroine X instinctively, that person isn't aware that these feelings of self-loathing and self-destruction lies in her Alter nature.
Her dangerous impulses to run amok may stay stable if the Master is a kind one.


Mysterious Heroine X (Alter) was available for summoning during the:

Valentine 2017 Summoning Campaign Fes.2017~2nd Anniversary~Lucky Bag 2018 New Year Campaign Lucky Bag
Valentine 2017 Summoning Campaign Re-Run Fes.2018~3rd Anniversary~Lucky Bag New Year Lucky-Bag Summoning Campaign 2019
16M Downloads Campaign Fate/Grand Order Fes. 2019 ~4th Anniversary~
Lucky Bag Summoning Campaign


  • Mysterious Heroine X (Alter) is the Otaku Version of Mysterious Heroine X from April Fool. Rather than having the same personality, what they have is the opposite.
  • She is 6th Class Alter Servant (Berserker) and she is also first ★5 Artoria Alter Servant.
  • Prior to her appearance in the game she was mentioned in FGO material as "「謎のセーラーX」".
  • The original idea of "Infinity Chocolate" is MARVEL's Infinity Gems and Infinity Gauntlet.
  • オルト・ライトニング (Alter Lightning) is the name of her lightning attack.
  • オルト・ライトニング (Alter Lightning) and her double-bladed lightsaber is a parody of Red Lightning and the double-bladed lightsaber used by Darth Maul in Star Wars.
  • Her Extra Attack animation is also a parody of Star Wars Episode 1 when Darth Maul killed Qui-Gon Jinn.
  • Her third skill Sovereign's Invisible Hand is her "オルタ・チョーク" (Alter Choke), parody of Darth Vader's Force Choke in Star Wars.


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