Fans of the story have started jokingly referring to it as "Grand Theft Grail War" due to how often Team Caster has to steal supplies from the other Masters.
This fic coined the phrase "Grand Theft Babylon" after Caster used his imitation Gate of Skye to dump all of Gilgamesh's "ammunition" into the Land of Shadows.
It's been called "Kidnapping: The Story" due to how many of Crow's problems have been solved by kidnapping someone. The list currently sits at Sakura, Shinji, Rin, Sola-Ui and Irisviel. Rin was accidental. She got herself kidnapped while looking for Sakura. A tradition most gloriously transmitted from master to disciple, as demonstrated by Shinji abducting Shirou in the sequel.
"You keep using that word. I don't think it means what you think it means... half-breed."
Crow tends to solve his problems with theft and kidnapping. Caster calls him out on it multiple times, to which Crow replies that he'd stop doing it if it stopped working so well.
Every time Kayneth is on the receiving end of Crow's thievery.
When Shinji asks Crow to teach him magecraft, the latter decides he needs some rules first. First rule? "Be nice to women". Shinji is understandably confused.
Scáthach is lounging around Dún Scáith and suddenly gets pelted with the contents of the Gate of Babylon. She initially expects Cú Chulainn to pop in, though she loses her patience very quickly. When a frustrated Gilgamesh tries to scry on his stuff, her patience has expired and she's raging at nobody in particular.
Heartwarming Moments: Despite being drafted into what amounts to a magical blood tournament, Crow will go out of his way to help kids in need. As soon as he had the ability and everyone was distracted, Crow immediately stormed the Matou mansion and burned the Worm Pit to get Sakura out. When Shinji's father left him behind, Crow took him with them so as not to leave him to Zouken.
He later acquired Sola-Ui's services specifically to remove the Crest Worms from Sakura.
Caster and Lancer immediately hit it off like friends, as fellow Irish legends with a healthy respect for each other. They end up in a duel to death, and Caster gives Lancer what he wanted: falling in battle against a honorable foe. No intrigue, no betrayal, only two warriors and their weapons.
Caster's genuine respect for his Master. When Lancer points that Crow is quite dishonorable, Caster gently yet firmly defends his Master as someone who will always uphold his word, no matter what. Even if it means protecting two kids while he's fighting a war, or sparing a foe's life because it would deprive Caster of a fair fight.
"Thank you." "You're welcome." The first and last words between Sakura and Crow.
Hilarious in Hindsight: The fact that the Caster Servant which is considered the weakest managed to outlast the Three Knight Classes (Lancer, Archer, Saber) & the Berserker (which is also considered a contender for the strongest servant), even personally killing the former three albeit with serious preparation and help against Archer as well as Saber being near death.
A bit of Fridge Brilliance when you consider that he allied with Rider and Berserker while killing a large number of Assassins. In FGO Caster are weak to Riders and Berserkers while having the advantage against Assassins. Crow managed to get the two Servants with a natural advantage against Caster onto his side.
Adding to the above, the events of the Fae Lostbelt imply that Caster Cu Chulain is an avatar or vessel with the power of ODIN. As in, the Norse Deity. Meaning that Crow, or whatever is responsible for placing him in the Nasuverse, summoned potentially one of the most powerful Servants in the War. To add an additional layer to it, Odin is heavily associated with wisdom, war….and ravens. Which makes Crow’s association with Caster all the more hilarious.
Crow pushes Gilgamesh's Berserk Button while Caster's imitation Gate of Skye steals all his weapons. Even Enkidu. Especially Enkidu.
Lancer gets the fair fight he always wanted in canon, albeit via Caster's runes. He loses, but goes out with a smile.
Crow stole the Thompson Contender and an Origin Bullet from Kiritsugu. He intends to mount it as a trophy after the war.
Kariya kills Zouken using the Thompson Contender. Specifically, he jams the barrel of the gun down the throat of one of the worms and pulls the trigger.
The final fight of the war begins with a giant mecha fight: Proto-Talos vs. the Wickerman. The Wickerman wins.
Despite being stabbed in the chest by Saber, Caster powers through and does a Your Head Asplode on Saber before casting a spell that negated Kiritsugu's Time Alter by physically slowing him to a crawl.
Caster activates his final Noble Phantasm: Ochd Deug Odin, using all eighteen runes in the air as a Kill Sat. Crow uses his final Command Seal to have Caster nuke the Grail with it.
Remember the oddball Assassin who found one of them getting assassinated amusing? He survives.
By the end of the Grail War, Crow has managed to accrue an impressive list of accomplishments.
1) "Won" the Holy Grail War.
2) Defeated both Tokiomi and Kayneth in single combat.
3) Killed Kiritsugu with help from Caster.
4) Prevented the Great Fuyuki Fire.
5) Arranged for the deaths of Zouken and Gilgamesh.
6) Semi-intentionally engineered the survival of nearly all of the Masters (Except Kiritsugu and Irisviel) and two of the Servants (Rider and Assassin).
Gilgamesh gets one long moment where he lives up to his out of universe hype. After breaking out of Ionian Hetairoi without using Ea, he tanks Ochd Deug Odin to the face and comes out without a scratch (though most of his Noble Phantasms were disabled and his parameters were reduced by a rank). Even after his defensive Noble Phantasms, Sha Nagba Imrue, and the Gate of Babylon are disabled (including his nigh-indestructible armor), he still put up a hell of a fight. Butt-naked and wielding only a pair of nameless wands, the King of Heroes still killed Berserker outright, disintegrated half of Saber's body, and knocked Rider out of the sky before Caster managed to finally kill him. Even then, he was still trying to get to Crow with the intention of brutally murdering him.
Near the end of the War, unaware of Assassin's survival, Crow sees the rising Greater Grail, and realizes that with Gilgamesh's death, it's filled to capacity.
Sakura. Dear god, Sakura. Even after being saved, what happened to her took its toll. She still doesn't talk - at least, not to Crow - and her interactions with her sister are noticeably stilted.
When the Matou House is attacked by Crow and Caster, Byakuya immediately flees while leaving his son behind. Shinji knew his dad wasn't a decent person, but realizing he doesn't even care about his flesh and blood just hurts.
Caster's point-of-view reveals he's more affected than he lets himself show by the fact he killed his own son. His reaction when his Master faints is to immediately panic, because Crow looks like a teenager and his falling reminded Cu too much of Connla's death.
"And so ends the legend of Diarmuid, First Knight of Fianna". He died in a honorable battle against a foe he respected... and broke the curse on Saber's wrist for his opponent to have a chance to fight her at her best.
After being stabbed in the chest by Excalibur and using his last drop of power to destroy the Grail, there was no chance for Caster to walk away alive. He spends the time he still has with his Master, reminding him the grimoire he wrote because Cu knew he wouldn't be able to teach Crow afterwards.
In the epilogue, Sakura mentions Shinji crying for the "Blue Man". Because he was kind of his sensei by Crow, but he also was a hero, and heroes sometimes die.
Your Mileage May Vary moments for The Puppeteer's Bodyguard.
The first chapter opens with the breaking news of Rider "... challenging President Clinton to honorable combat?" Word of God has it that Clinton had to be stopped from taking him up on it.
Waver accidentally invokes Klingon Promotion when he kills Old Man Acht, with the Einzbern Homunculi acknowledging him as the new Lord Einzbern. Cue poor Waver fleeing to America and the Homunculi following behind to make him accept his new status - sorry, Waver, but the multiverse wants you to be a badass.
Crow's puppet familiar owns a functional digestive tract. He uses it as a diversion by making the bird poop on a guard's head.
Because Crow told Rin about a first-generation magus living in Fuyuki, poor Shirou wakes up tied to a chair while our favorite tsundere is yelling at Shinji for pulling a Crow on him a.k.a. kidnapping someone For Their Own Good.
An offscreen one. The first time Crow met Cormac, the latter chased off three thugs trying to burn down his pub by pulling a greatsword off the wall and going at them. After that, Crow eats there at least three times a week.
Rider, Waver, Kirei, and Assassin pulled a four-man siege of Castle Einzbern, with the Servants and the Executor tearing their way through dozens of combat homunculi easily.
However, Old Man Acht doesn't go down without a fight. The elderly golem ripped Assassin in half with his bare hands and took an arm and leg from Rider using alchemically-enhanced cables. Fortunately for both of them, such injuries are neither lethal nor permanent for Servants.
The one who finally killed Old Man Acht and Golem Einzbern? Waver. This entire interlude was a CMOA for the kid. Using a necromancy-enhancing mystic code that Crow stole from Kayneth, he summoned a shade of Kiritsugu to guide them through the wards around the castle. While the others were busy fighting, he was messing around with the internal workings of the castle. When he dealt the final blow with another mystic code, his alterations shattered the mind of Golem Einzbern by transmitting the pain inflicted on its terminal body (Acht), effectively killing it.
"Unfortunately, Hitler still came to power. Fortunately, Paul von Lettow-Vorbeck still told him to "go fuck himself."" -Rictus
Crow's ability to learn Rune Magic at an extremely rapid pace finally got an explanation: He's unwittingly hemorrhaging memories in exchange for an increased learning rate. By the time he realizes it, he's already forgotten a number of minor memories, including what his parents and brother look like. He has no idea how to stop it and it borders on Tearjerker when he mentions what he's done to hold on to what he still has (writing extensive journals, picking up items that remind him of his childhood, etc.).
Turns out, the Mask has an avatar capable of making itself visible to spiritually sensitive people like Kirie Fujou. Its general shape is described as a glossy-black crow with three faces, the eyes of which are a bloody red, with each of its mouths filled with sharp fangs and each of its toes ending in gleaming steel talons. Additionally, it's started showing that it can influence the world around it without Crow knowing. All of this implies the Mask's maker and power source is none other than The Morrígan.
