Because the file is so big, and uploading the file takes forever, I've released a small patch which fixes some errors and adds a few new twists to the mod... If you plan to download this mod, don't forget about the patch, it's only 10MB size:
http://www.mbrepository.com/file.php?id=3216

This mod features INSANE difficulty, every item powered up, every troop's equipment changed, every troop is much stronger, 500 new items, around 150 new troops in total, and a lot of little tweaks and changes in the game scripts.
Here will I list the features(note I will update this list from time to time)
Note that this is an re-edited version of the original Native Expansion mod, so all credits go to the original NE team...

1-You as a player start super-strong, around 45 STR and AGI, but even this super-strong character wont be much of a help here as you will face MUCH stronger troops.

2-You get lousy starting equipment and it's really hard to even start playing. Even your money is pitty, a mere 50-150 denars.

3-Bandit parties that roam through Calaradia are all redone. All bandits have an upgrade path now as folowing:
Sea Raider->Sea Warrior
Forest bandit->Forest Raider
Mountain Bandit->Mountain Raider
Steppe Bandit->Steppe Raider
Looters have been removed as a stand-alone party, they are now members of a much larger and more diverse "Bandits" party.
The bandits have been made stronger, but their equipment is a little lousy, so you don't get any good-quality gear from them(well, except sea raiders, but they are also a lot stronger than other bandits, especially Sea Warriors)
Anyway, if you want good loot, you must go after lords and patrols. Patrols are smaller parties of 30-50 troops that, well, patrol the territory of the faction they belong to.

4-Some skills, most notable Personal skills can be upgraded to level 15, while other skills have a max level of 10.

5-Due to the high starting attributes, it is possible to reach maximum value for attributes, and that is 63. You actually CAN add points to an attribute that is already at level 63 but that point will be wasted, it will have no effect.

6-added an additional 400 items and around 150 new troops, and new mercenaries.
-every item is made stronger and faster. Item weight is also changed, every weapon, even the original native ones, edited and redone, especially the armors(plate armors with an weight of 40+) so if you stack yourself with as much armor and big heavy weapons it will heavily slow you down.
-the plate armors are very powerful, way above any other armors, but also very rare and expensive. But they come with a little-so-annoying thing...weight...and I really mean it. The difference in speed of a plate armored unit and one in leather armor is immerse. Although in the end it really comes on how thick your armor is, armor weight mostly disadvantages the player and actually, using light plate and mail is much more efficient. Even with 10 athletics and 60 AGI you will still be really slow with any plate armor you wear(well, except one). This limits the number of plate armored units on the battlefield and ads a lot of balance to the game.
-Food is a big Aspect of this mod's difficulty. Every food units holds a different amount of food, it's not every food 50 units, and beef 70. Every food holds a different amount of units( that is less than 50 in 90% cases) and their cost is doubled.
-crossbows finally catch up with bows. CBs are much stronger and much more accurate than bows and have the highest base damage of any weapon in the game. So it's actually now a choice will you play with bows or crossbows. They are finally in balance.

6a-There are two unique merchants that appear in taverns called artificers who sell special weapons. The Rare artificer sells unique items and weapons of Calaradia, and the other sells very powerful items that cannot be found anywhere else in the game.

7-The Factions:
-every faction edited, remade, balanced, and powered up(a lot).
-every single troop in the game remade and made stronger.
-factions are color-coded now, but you will understand it once you see an entire blue, or red army, or a green one.
-every faction has three troop trees now, a regular one, a noble one, and elite.
-lords and kings are super-powerful. Fighting them one-on-one is really tough, not counting their army, and facing them in a tournament is a nightmare. Lords have around 300HP and carry 300-500 troops. Kings have 500HP and carry around 1000 troops.
-towns usually are guarded by a thousand troops. Castles around 600.
-Training troops is a lot harder, you'll need a lot of time to train troops to the end of the troop tree, but when you get there, it's worth it. The end-troops are super powerful, and make a really big jump from the troop they've upgraded from. For example, a Swadian Champion, which is the second last troop in Swadian's infantry troop tree, has 30STR, 14 AGI and is level 35 with weapon stats around 230. When upgraded into the Gothic Knight, the last troop, it's stats skyrocket to 56STR, 32 AGI, Level 53 and weapon skills of 320. That's just one example. While training troops throught the troop tree, they gain 2-5 levels and a +3 to + 5 STR AND AGI bonus per upgrade. But when upgrading to the last troop, which is considered an Elite Troop, the stats skyrocket by +20 or even +40 in some cases.

-Swadians come back with their powerful Cavalry, stronger than ever, able to take any enemy in any situation... The famous Swadian knight can be upgraded numerous times now to a baron, cavalier, paladin, duke, and much more. Sergeants also gain some nice upgrades to Blade knight, Gothic Knight, Royal Guard and Heretic Minion...

-Vaegirs strike back with their deadly marksmen, capable of destroying entire armies from afar. Of course, there is a level beyond the Vaegir marksman, as well as the guard. However, Vaegir cavalry is completely redone, they prefer fast horses and deadly weapons over armor which makes them impressive in offense, but lack a little defense.

-Our friends from the North brought tons of new badass axes and hammers, ready to smash any opposition to pieces. With their improved huscarls and archers, Nords rule in siege and hills, and proudly carry the mark of the toughest infantry in the game...
Or is it?...

-Khergits are no more... Now Zarrakians hold the wide steppe field, and cast the old Khergits in the shadow with their skill and precision in horse archery as well as in a fierce melee... Zarrakians are the soldiers who will kill the fastest, but also who will die the fastest. They are incredibly offensive, but at the same time, pitty deffensive.

-Rhodoks have crafted superior advanced new weapons and have brought them to the light of the day, ready to face anyone in Calaradia and take advantage of the element of suprise. The element of new weapons of course. Rhodoks still prefer polearms over anything else and you will witness their love for polearms here more than anywhere else.
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-You will gain loads and loads of experience points in this mod. For example, killing a Swadian infantry will net you 800 EXP, a Sea Raider 600, A Cavalier 1500, a lord around 7000, and if you manage to defeat a king, you are 30000 EXP points richer.

8-Mercenaries, all redone. I have reduced the number of mercenaries to make them more compact and easier to manage. Bot I have expanded their equipment, making it really wide, so mercenaries come with a lot of different weapons and armors.
-Mercenary Swordsman
-Mercenary Lineman
-Mercenary Knight
-Ronin Mercenary
-Chargers and Assaulters
-Slave Hunters
-Dragon Knights
-Penetrators

9-Dark Knights
If you have asked yourself what does this "Or is it?..." line say in the description of the nords? Well, there is a sixth faction so to say. id doesn't own any land and you don't have a clue that they exist at all... untill they arrive in Calaradia at day 75 and break the balance of the game.
They are the nightmare of this game, with every troop having 80+ STR adn insane 300-800 weapon stats. No army in Calaradia is a match for them and it requires some serious thinking and strategy to defeat them as beating them with brute strength is actually impossible.
Skaar Deathrune, the Dark King, and his four Dark Lords, Sirius, Atlas, Tantius and Gracius.
Dark Knights don't spread wide, they concetrate all their army to one or two castles and put a few thousand troops to guard them, and from there they eat Calaradia bit by bit untill they're stopped. But stopping them is the problem.
Dark Lords lead an army of 400-1500 insanely powerful troops and the Dark King leads a horrifying army of thousands...

10-The companions
All 17 Companions in this mod are sorted by factions, and once they become leaders of parties, they train and recruit troops from the faction they belong to. All Companions represent a certain elite troop of the Faction they belong to, their equipment is like the elite troop's, and they are much better in skills and weapons than the elite troop they're representing, making Companions very useful in battle as well in party skills as every companion has at least in one party skill level 10.
(note there is probably a lot of confusion in the Companion's dialogue I can't seem to fix, so please, have patience and best of all, don't bother reading the text)

Remus-Tercio Pikeman
Remus is the most expensive Companion in the game, but he's worth it. He wears the best, but not the strongest, buyable armor in the game, the Morion Plate armor, and instead of a steelpiercer pike though, Remus uses a big Bardiche, making him a very offensive unit, and thus still very fast, due to the Morion armor's low weight.

Velid-Ivory Archer
At a cost of 10000, Velid is an excelent marksman, with deadly precision, and a insane level 10 spotting skill. Although weak at defense, Velid can put up a good fight even in melee, but you won't find a better archer anywhere in this land.

Galeas-Swordfighter
Galeas is a true leader and commander, with both leadership and training at level 10. Once he gets his own party, Galeas will pretty soon have elite troops in his army and plus a bigger army than other companions's. Regarding his abilities as a leader, his usefulness as a soldier aren't to be underestimated. Galeas is an expert swordsman, fast, and intelligent fighter, with a sword and steel shield.

Thorgrim-Rock Crusher
Now this is the strongest Companion in terms of strength and endurance, capable of smashing through any armor with his great hammer. His tremendous offensive power is also backed up with high armor, allowing him to sustain many hits while cracking the skulls of his enemies.

Bahestur-Kamuluck
Bahestur if a fast, deadly horse archer, capable of delivering massive damage without being hit at all, because he lacks good armor, he uses a long 360 reach lance and Ivory bow.

Erevan-Iron Guard
Clad in heavy full plate armor, and with an Antarian shield, Erevan is the most durable of all the companions.

Aurelius-Halberdier
Aurelius doesn't require any cost to join you, and he is terribly useful as a soldier for stopping cavalry, and massacring smaller, weaker troops.

>the other companions will be updater soon
Jinnai-Orlok

Alastor-Heretic Minion

Vorian-Praetorian

Rolf-Huskarl Champion

Sahar-Elite Kataphraktos

Nizar-Bashkir

Richard-Paladin

Aragon-Gothic Knight

Kuraf-Oprichinik

11.And a lot of other little tweaks and changes like:
-merchants have more money
-removed all female units besides peasant woman, and replaced them with male ones.
-looting skill has more effect
-morale system (not made by me)
-wounding system (not made by me)
-prisoner management and leadership have their effects doubled
-faster gameplay, everything from players, horses, weapons, fastened.
-and a lot of others I can't think of now...
Please tell me what do you think of this modification, I want to share it with others. And I'm really curious to hear people's opinion