Darj is like the spiritual cousin of Saber/Artoria Pendragon, with the convergent evolution of gender-swapped King Arthur outfits!

they failed to give Kay the cowboy motif. :(

To be clear, it's not that they're portraying accurately characters from history, but they're parodying the cosplaying of the History Girls (Team Hippo). The event is called History Student Gaccha (ヒストリー生徒ガチャ) after all.

That being said, I wonder what the reference point is for Nishi Kinuyo, Ogin, and Marie. Darjeeling as King Arthur and Kay as Lady Liberty seems obvious, but those three are less clear to me.

References

• Official site(jp): Announcement

BrokenEagle98 said:

That being said, I wonder what the reference point is for Nishi Kinuyo, Ogin, and Marie. Darjeeling as King Arthur and Kay as Lady Liberty seems obvious, but those three are less clear to me.

The gun and the crest in her hair and on her clothes make it obvious Kinuyo is Nobunaga, and Marie is mimicking the pose in Napoleon Crossing the Alps with her raised hand.
Based on the shimenawa around her shoulders and her pose, Ogin might be Ishikawa Goemon.