A Berserker-class Servant in [[Fate/Grand Order]] who is the [[dark persona|alter]] version of [[Mysterious Heroine X (fate)|]]. Unlike other versions of [[Saber Alter]], Heroine X Alter retains [[Saber (fate)|]]'s iconic [[ahoge]] while wearing her school uniform. While her initial appearance is heavily influenced by [[Master Artoria]] (along with [[glasses]] for extra appeal), her later ascensions make her look more like a Sith Lord from [[Star Wars]], complete with Force lightning and dual-bladed lightsaber.

Gained [[Mysterious Idol X Alter (fate)|an idol version]] for the Grail Live! event.

[b]Character Design:[/b] [[Takeuchi Takashi]] (as Master Artoria); [[BUNBUN]]
[b]Voice Actress:[/b] [[Kawasumi Ayako]]

h4.Costumes

* [[mysterious heroine x alter (first ascension) (fate)|First Ascension]]
* [[mysterious heroine x alter (traveling_outfit) (fate)|Heroic Spirit Traveling Outfit]]
* [[mysterious heroine x alter (princess of red bean paste) (fate)|Princess of Red Bean Paste]]
* [[mysterious heroine x alter (second ascension) (fate)|Second Ascension]]
* [[mysterious heroine x alter (third ascension) (fate)|Third Ascension]]
ヒロインXオルタ 謎のヒロインXオルタ 謎のヒロインX〔オルタ〕