the story started very well, avoid describing too many comparisons with the canon.
Will Ilia, thanks to the growth given by the levels, mitigate her problem?
You will certainly want a filorial that will be chosen as successor by Fitoria also to keep an eye on them; better not Firo.
Ilia vs Atla, cat fight for Shirou; Fhol has a crush on Ilia, she doesn't shit him.
Ilia and Rider will surely notice Naofumi's animal charisma which should be a D or at most C.
Motoyasu has a fascination against E. women.
Remember that Shirou's group should be the protagonist who will act as a mentor for the other three.
The other heroes shouldn't get NP At least for quite a while because they have to hide their skills and then only those of a lower level or one that suits them particularly.
Shirou will try to develop his sword with all the healing skills he can and by copying the NPs giving priority to those who can help Ilia.
Their main objectives in order will be: to get Yggdrasill to heal her, to create a safe haven, to help the other three, to deal with the waves and slavery.
Have you changed the color of the sword's gem in order to give Rin the vassal weapon in possession of the king?
Rider got a new body and will take the vassal whip?
They after discovering the changes in the jellyfish will surely try to summon Saber which could end up inside a dragon egg or be correctly summoned but in the future obtain the fragments of the emperor dragon.
In case of a correct summoning, you could also blow up Morgana who is also connected to Avalon, without making her an enemy but making fun of Arthuria and making her jealous with Shirou.
Except for the two of them, they shouldn't try to call any other Servant to avoid getting Merlin out. Too many evocations would spoil history.
Will the Sword gain wisdom perhaps with a job or level up?
cursed weapons will help Shirou to fully regain emotion.
Maybe he could already be subject to all the cursed series since he has been in contact with Angramayu?
In the future you should have at least one character from this world join his group who is not a monster.
I think at least two 6/8 parties would be needed that you could fill the seats with familiar monsters which don't require much character development; they could be something like:
Ilia a Filorial, Medusa a hydra, Sakura a dog, Rin a shadow cat, Shirou a dragon / Arthuria, Arthuria not dragon a lion and Morgana a crow.

Lol they've completely destroyed the plot already i love it. I'm really looking forward to seeing them fucking dismantle the slave trade, too many fics just dont pay adequate attention to it and crossovers with the MC inserted as the Shield stick to the plot even though character traits would demand that the slave shop be burned to the ground so im glad to see that you're staying consitant here. Will he use Rule Breaker to remove the slave crest? it would definitely be in character for Shirou and within the power of the NP.

I love it man! This is going to be a great story! (if it's continued...no offence) I love to read more of it. Favorited and anticipating the next chapter!

To clarify something, you only mentioned a girl with green hair, and then called her Raphtalia?

What os this traversty?! EXACILUBUR? I demand satisfaction! It's Excalibur damn it!

more

I enjoyed this chapter but all of the paragraph emphasizing on the differences feel REALLY over done, and are super distracting.

Fuck canon also if I remember correctly the main bad's name is Medea so I'm really waiting for The Emiya family's reaction to that clusterfuck

Fucking Cannon is fine and All but
I noticed that you heavily side with Naofumi, considering he is the Mc of Shield hero.

[Sigh] ... Shirou is a bit naïve throughout this chapter even though he is older than the other Heroes. But first I want to apologize for the wall of text below.

I'll start with the elephant in the room; Shirou bringing down the Slave Trade would result in collapsing and crashing Melromarc's economy instantly. No economy no money... and no money no standing military army. While the Heroes have fought the waves, each country's army has had a significant role in containment of waves to a degree and without any standing army, the world would be run over by monsters inside of a month just like Glass's world.

The Slave Trade is an necessary evil even if people find it distasteful. In the other countries of this world, Slavery is legal however depending on their political infrastructure in each country, Slaves are treated well and there are regulations to ensure that there is no mistreatment. Unfortunately, Melromarc is one of the few where Slaves are treated like dirt largely due to both Aultcray Melromarc's deep-seeded hatred of demi-humans and also due to the Church's influence.

I don't agree with how demi-humans are treated in Melromarc but the sad fact is Slavery is a necessary evil. You take down Slavery and you'll end up destroy both the country's economy and the infrastructure, hence why Shirou is naïve in his assumptions.

For the second thing, both Motoyasu and Itsuki in your story don't act like their counterparts in the books or anime show. In fact, I don't recognize them at all as they are acting completely out of character. You could argue that it could be because of "Shirou's influence" but that would be a fallacy. Even if they believed that this wasn't a "game" anymore and that they could die, they would and should still be arrogant, snobbish and selfish to a large extent. Their flaws didn't just sprout out of the ground one day when they arrived in Melromarc. Their flaws came with them to this new world. For example:

Itsuki's sense of Justice takes him to the extremes with trying to bring down a tyrant king in another country and ends up not even bothering to stabilize the country with fair and just rulers. He essentially replaced one tyrant king for another tyrant oppressor. It's for this reason why his Curse series is "Pride".

Ren's sense of needing to the 'the strongest' is so strong that his greed and gluttony to gain powerful monster materials ends with with killing a dragon, taking body parts for materials to strengthen his sword and then takes off, half-arsed and not even bothering to destroy the dragon carcass...which ends up poisoning an entire village. His curse series is Greed and Gluttony.

Motoyasu sense of lust and envy is probably the more troublesome of all four heroes. He is so blinded by his lust that he doesn't seem to realize that it might be wrong to lust after Filo, a ten year old girl. He is so blinded by lust and envy that he is blind to the truth and takes the word of a 'pretty woman' over anyone else, any day of the week, even if said woman was lying. His curse series is Lust and Envy.

Naofumi is different in that his original flaws was being too trusting and too naïve that he was easily betrayed in the beginning which in turn resulted in him unlocking the Wrath series. Later on as his character developed, he gained a new Seven Deadly Sins Series and eventually the Blessed Series which is similar to the Wrath series but have no drawbacks and is much more powerful.

My point is, they had these flaws when they got isekai'd to this new world. They already possessed flawed emotions and ideals before coming to this new world...meaning that Itsuki, Ren and Motoyasu were already assholes to begin with...and changing their characters to be "good guys" doesn't feel realistic. The Legendary Items take on the characteristics of their owner's strongest feelings and turns it into a curse series, which in turn empowers the heroes beyond normal strength and limitations. But the feelings were already present...even at the start of the manga and anime, even if they hadn't unlocked the curse series yet.

With changing their characters to be "good guys", you've effectively changed the entire future events of all of the story Arcs. Naofumi will never be as powerful if Itsuki and Motoyasu don't turn on him. Motoyasu could potentially be assassinated if Malty or the Church realizes that he isn't an easy puppet to control. Itsuki would end up in the worst out of the others. He already had an unhealthy notion of being the strongest of the Heroes and the fact that Shirou Emiya is in this story, who is undoubtedly the most powerful of all the Heroes is present, would cast a major shadow over Itsuki.

I don't even want to know just how many Curse Series this guy is going to be swallowed up with. It was bad enough that he thought Naofumi was using a "cheat" when Naofumi killed boss monsters or carried the team by using the Wrath Series, but with Shirou here casting a giant shadow over him ...Itsuki could potentially be 10x worse than in the canon books and anime show. That's how strong his sense of superiority is and no good will come of it. Itsuki hero complex was bad enough in that he would purposefully and intently wait until people are in a crisis before acting so he can "save" them in heroic fashion. It's for that reason why Itsuki is the worst of all the Legendary Heroes.

this shows promise but it also feels off, for lack of a better word. also it's senpai with an n not sempai with an m

Welp

Overall good chapter. Can't wait for next update.

you actually made some of the unlikable characters seem decent this chapter, except bitch princess and time to see Shirou burn the slave trade until it becomes charred ashes

I like these bond! It's so good to got to see them be good together