When Shirou uses time thaumaturgy on his projections, he ends up feeling himself the backlash. This is because his projections are not material objects so much as parts of his inner world shifted into the real world.
The meaningful names given to the three mystic codes built from the remains of Kiritsugu all match up with their abilities.
Natalia holds the concept of "Severing". Natalia was Kiritsugu's Parental Substitute that he killed with his own hands, severing their bond in that way.
Maiya was Kiritsugu's partner, one he half raised, who bound herself to him despite him wanting her to walk away, ultimately leading to her death.
Finally, Kiritsugu itself; aside from his name being formed from the same kanji as "Severing" and "Binding", it's a sword that utterly destroys the target. Just like, through a random chance, Kiritsugu set things up to completely destroy the normal routes and possibilities for Fate/stay night.
Shirou's statement that breaking his timeless projections would require an act of God is true because Berserker is Heracles who ascended to Godhood which gave him Rank A Divinity.
Archer actually gets extra information he could never get in any other timeline because he was dead by then, thanks to the mind link between him and Shirou, and he gets to put it to good use: that Rule Breaker can help stall Angra Mainyu in Sakura.
In this timeline, Emiya Kiritsugu is a proper Heroic Spirit, and Princess!Caster can even find his legend. This means Luvia's research on Kiritsugu actually contributed into creating the beginnings a legend for him!
Even better, this is probably what allowed Luvia to summon an improbable redeemed version of Medea, one that never became the Witch of Betrayal, in the first place!
The fact that Marjata invoked Witch!Caster outright implies at heart she is as bad or worse than Atrum Galliasta.
A lot regarding Shirou's condition and future after the War, with mutilations and a probably now very visible vampiric signature.
How many people did Shirou kill or maim beyond help? How many people got killed or put down by Taiga and her family or Kiritsugu's machinations? Monster who saves, indeed.
How close Shirou got to getting a Sealing Designation, even without his Reality Marble revealed; because he can do perfect projections of Avalon, but managed to explain it in a way that stumbled upon replicable groundbreaking discoveries regarding the requirements for performing perfect Gradient Air.
This also glosses over the fact he really isn't bound by the stated requirement of "possessing the original" since he has his Reality Marble memorizing every weapon, and since his Gradient Air is more shifting stuff from UBW to the real world than anything else.
Also he was damn lucky that the only Noble Phantasms he replicated in front of Barthomelloi were Avalon, and the Mace of Odo, for which originals were in front of him, helping skew her understanding of the situation.
Not quite valid anymore as of Chapter 56, as they made a big deal of Angra Mainyu's curse... which Shirou can replicate from memory. If he can replicate that from memory, then Noble Phantasms aren't that much of a stretch anymore.
As of Chapter 60, the cat is out of the bag and "Unlimited Blade Works" has been spelled out by Waver to Barthomelloi, along with the fact it is a Reality Marble. She STILL stays her hand from slapping a Sealing Designation on everyone involved out of spite because they and the derived research are JUST THAT useful.
A hefty helping of it for everyone in the story, as they get their hands on Kiritsugu's notes and thus on a full info dump of Fate/stay night including bad ends.
Realizing the Holy Grail War is over, and Shirou completed his Reality Marble upon seeing the work done. In canon, he would complete it in the heat of the fight. The implication is that Shirou did not go all out, or has more room for improvement, and that he WILL use the completed version in the upcoming conflicts that are now uncharted territory for him.
People are now digging into Shirou's genetic background, and Lorelei is poking at the question everyone has been asking: How did Kiritsugu get these dreams?
