This Craft Essence can be obtained by bringing Mysterious Heroine X (Alter)'s Bond Level to 10. It comes at max level with all limit breaks.


Normal Effect
When equipped on Mysterious Heroine X (Alter),
While she's on the field, Increases damage against Saber-class by 20%.

Lore Edit

His official designation is, Servant AUX Voroid "K6-X4". It is a Servant auxiliary high-performance robot meant for combat and navigation assistance. A trusted partner of X Alter's ever since she could remember, who she nicknamed "Black Knight-kun".

His character is bad and so is his tongue. He's not fit to appear in public. He completely looks down on humans, and will even ignore orders, but he is loyal to the end to X Alter alone.

In his head, minute Alternium crystals are buried, which are synchronized with X Alter. By the way, its body which is reminiscent of an ancient helm is the repurposed head of a rampaging mechanical giant which once turned an entire planet into scorched earth.

"Is that so... poor you.There are people who have been treated so cruelly too..."



サーヴァントAUXヴォロイド“K6-X4”。 戦闘・航行の補助を目的としたサーヴァント支援用の 高機能ロボットだ。 X・オルタとは物心ついて以来の相棒で、 「黒騎士くん」と名付けられた。

性格は悪く、口も悪い。そも人前に現れない。 人間を完全に見下し、命令されてもまず無視するが、 X・オルタにだけは忠実に尽くす。

頭脳には微少なオルタニウム結晶が埋め込まれ、 X・オルタと同調している。 ちなみに、古代のヘルムを思わせるボディは、 過去、一惑星を焦土と化した暴虐の機械巨人の 頭部パーツが流用されているらしい。

「そうだったのか……可哀相。  ひどい仕打ちする人がいるものだね……」 「――――――」