Fate grand order: Epic of Remnant: The master who stands in for the orginal

Prologue

Ritsuka Fujimaru or actually Ritsukas because there are actually 2 of them, they are siblings, who had managed to do what could have been considered impossible, they saved humanity from being incinerated. The cause of this? Solomon, or in better terms, Goetia, the one who's plan was to erase all of humanity's history. They managed to defeat him and return everything back to normal.

This was only possible to the Ritsukas if it hadn't been for the following:

The hard-working staff of Chaldea

Everyone's favorite old man in a woman's  body, Da Vinci

Everyone's favorite Kohai, Mash

The beloved doctor that sacrificed himself to save the Ritsukas from insanity, Dr.Roman, may he rest in peace (I cried when Mash died and I cried, even more, when Roman sacrificed himself.)

And the very loving and supportive boyfriend of the Female Ritsuka, Red, he is a black-haired and red-eyed guy standing at 172 cm

"Fou...? Fo, Fouu!!" A creature was heard

"Something's licking my cheek..." said a female groggily

Both the Ritsukas open their eyes to see Mashu, really alive and Fou, and Red as well.

"Senpai---!" Shouted Mashu with tears in her eyes

She then runs up and embraces the male Ritsuka

"Gudako!!!" Shouted Red as he did the same with the Female Ritsuka

"Returning the hug ---!" Both the Ritsukas shouted like Mashu and Red

They returned the hugs, like some nameless swordsman that could be found guarding a remote temple gate.

"Yes, good morning, Master! I, Mashu Kyrielight, have returned alive!" Mash announced joyfully 

"What on earth happened?" Both Ritsukas questioned

Mashu says that she does not really know herself and nither does Red. When Mash came back to her senses, she was already at the Rayshift coordinates. As for Red, he said that everything went pretty ok despite both Ritsukas almost dying, the only thing abnormal was Mash coming out of the coffin. Chaldea though she was gone after she was evaporated by Goetia's noble phantasm and she was in perfect condition none the less.

"I feel like I was sent there with some very gentle words, but I just can't remember what they were." Mash said deep in thought

Fou's voice woke her up, and immediately she saw the other 3 running towards the retrieval point with the male Ritsuka holding her hand bringing her along with them.

"And then, like in a dream, I stretched out my hand towards you... Fou-san, do you know anything?" Mash asked Fou

"Fou, fou?" replied Fou

"Alright there, it's about time to break it up, okay~ You guys are still in front of all the staff, you know~" Said Da Vinci looking directly at the little show in front of her with all of the staff behind her

It sure was a romantic sight to behold indeed, Mash and Gudao (Male Ritsuka) were holding hands all couple-like. Red carrying Gudako bridal style as if they were a married couple.

Blushing, Mashu lets go of Gudao and moves away quickly, while Gudako, blushing as well, hides her face in Red's chest.

"Da Vinci-chan!" Shouted Gudao and Red

Da Vinci bids the 4 of them good morning. It seems that it had taken the Ritsukas about an hour to awaken from the coffin, but she assures you that all their vitals are normal. They have returned to Chaldea successfully, without harm and that means...