This resulted from reading revdb's Insane Gudako and my own frustrations in FGO (with the exception of Karna). I have permission from revdb to re-use this concept for my own story. Also, Gudako isn't as crazy as the one in Riyo's comics. She's insane…in a special way. Enjoy!

It should have been a regular day at Chaldea. Well, as normal as a day could be when the rest of humanity was theoretically destroyed and the future resting on the shoulders of a single human girl. A break day had been announced, much to the delight of the Servants, who were either sparring outside or doing whatever they wanted in the common rooms or their own rooms.

Robin and Drake were conversing when they heard a scream of frustration around the corner. Recognizing the familiar voice of their Master, they sighed in resignation and went to find their Master with an angry look on their face.

"Captain Gudako..." Drake started, but the orange-haired female Master waved her off.

"It's fine, it's fine," Gudako said, her initial anger gone to be replaced with dejection. "Your rate-up day was today and I rolled nothing but Black Keys."

"If you're trying to summon me, why didn't you just ask me to roll for you?" Drake asked.

"Remember the last time you did? You got me 4 copies of Gilles and a billion Black Keys."

The pirate sighed in resignation. "Right."

"Asking me is out of the question then," Robin said. "I remember the last time I tried, I ended up getting you nothing but mapo."

"And I burnt them for mana prisms...this game is giving me a headache," Gudako groaned. "I don't get it. I've summoned all of you here to Chaldea and I can't even get most of you in a mobile game! Where did I get all the E-ranked luck from? I give up...maybe I should ask Dr. Roman for some more money since Jackie's rate-up day is in a few days...or I should go drop off the Black Keys I just summoned here today to Amakusa...whatever. See you around, Drake, Robin."

The pirate and the mercenary exchanged concerned glances for their Master as they watched her walk down the hallway.

Gudako lay on her bed, busy farming hands. While Drake hadn't been summoned, she had managed to get Medea to NP5 and decided that farming some Caster EXP cards wouldn't be too bad. After defeating the last wave, her phone's battery level had dropped to 5%. She plugged in her phone and began listlessly scrolling through her Servant list. "Ugh...3 stars, more 3 stars, 2 SRs, there's Mashu..." Her voice trailed off as she saw her one beacon of hope in the accursed game known as Fate Grand/Order.

Karna. She had somehow summoned him when she first downloaded the game (it had already existed for a while before she decided to play and she now had him grailed to 100 and his skills were nearing 10/10/10) and knew that it was the only time she'd probably have good luck in the game. Her prediction came true when she progressed through the game-no SSR ever came to her. Their rate-up days produced even more Black Keys and mapo for her.

Gudako groaned and started rolling around on her bed. "I just want more SSRs in this stupid game that probably shouldn't have existed in this world in the first place!" She closed her eyes, moaning in frustration.

"Is that really all you want right now?" A voice asked.

Gudako's eyes shot open and she sat up. "Who is it?" Looking around carefully, she realized she wasn't in her own room, instead standing in some dark, empty place. "A dream...alright, who is it?" She asked crossly. "Solomon, if you're going to laugh at me, at least do it where I can see your arrogant face." Yet deep down, she hoped it wasn't the King of Magic. The last thing she needed to see after her failure at rolling another SSR was to see the face of the being that threatened humanity's future.

"You valiantly battle with your Servants for Humanity's future, yet when it comes to a mobile game, you're reduced to an ordinary fangirl with issues over not managing to roll Gilgamesh or Ozymandias. Come on, aren't you happy with Karna?"

"Of course I am!" Gudako said. "I just want more SSRs so I can blast the enemies easier, okay?! I don't even have an SR Archer to beat up Saber-class enemies and Robin just won't cut it. An SR Caster would also be nice and..." She started rambling, and the voice cut her off with a small cough.

"As amusing as it is to watch you agonize over your terrible luck in the mobile Fate/Grand Order, I have a proposition for you."

"Reveal yourself first before that."

"Sharp as always, Gudako." An old man with red eyes materialized in front of her, and Gudako gaped.

"You're that old guy on that 5 star Craft Essence!"

"That 'old guy on that 5 star Craft Essence' has a name, you know."

"Kischur Zelretch Schweinorg, I know," Gudako said, an astonished expression still on her face. "The Wizard Marshall and the Dead Apostle Ancestor who mastered the Second Magic."

"Oh, so you have heard of me! That clears things up, then?"

"No. What do you want with me? Going to tell me about a timeline where I fail and the world's going to burn?"

"No, but it did happen. Like I said earlier, I have a proposition for you."

Gudako's apprehension was replaced with curiosity. "What is it?"

"Have you heard of the Great Holy Grail War?"

"Yeah. Astolfo and Jeanne talk about it occasionally. 14 Servants divided into two factions of 7. Their's took place in Romania. Vlad gets really annoyed when they talk about it because he got betrayed by his Master in that war. Karna, Amakusa and Siegfried were in there as well, right?"

"Among other Servants, yes. Would you like to participate in it?"

Gudako gaped at Zelretch.

Zelretch laughed at the look on her face. "I'm being serious, by the way. With the Second Magic, I'll be able to transport you to another domain of the Kaleidoscope for a while, and you will retain all your knowledge and your magic circuits."

"Uh, I have a world to save here?"

"Relax, it's only going to be for a few days. You guys are nowhere near finding Solomon."

"What's in it for me and why are you even asking me?"

"Just an experiment. As for what's in it for you...you're low on Saint Quartz, right?"

"Down to zero," Gudako confirmed with a dejected face.

"500 quartz and complete knowledge of the events in the Great Holy Grail War, plus your Servant will be Karna."

Gudako's eyes shone. "You're serious?! 500 quartz?! And Karna?! Wait, you're not joking, right? I've heard way too many times that you're a complete troll."

"I'm being serious this time. 1000 quartz, then?"

At this point, Gudako had literal stars in her eyes.

Zelretch chuckled at her expression. "Let's shake on it, shall we? I'll transport you to the Clock Tower and handle most of the negotiations. You get 500 quartz as an advance payment." He held out his hand.

Gudako nodded excitedly and took his hand. "Deal."

Zelretch is a troll. What would happen if he met Merlin?