Alright, this one really isn't easy to answer but since it involves another topic that's going around at the moment i'll try and explain.

Basically the chaos script is heaviliy edited. I'll try and explain in pratical terms most of the stuff it does from the player's perspective.

You will ahave to bear with me because it's been a while since I created this version and its changed a lot over the different versions so I'm not sure everything thats a deviation from vanilla.

Firstly the dead easy stuff, number of hordes, waves, horde sizes are similier too if not the same as the vanilla script. (most chaos difficulty mods change these numbers)


When a chaos horde is spawned it has two stages.
One is early game, the other is late game (the one with archeon)
What this script primarily does is change what shows up.

For example: The chaos faction to beastmen faction % is tweaked to allow for more UC hordes.
the composition of each army is changed so it's roughly like this:
-- 60% Infantry
-- 20% Calvary
-- 10% War Engines
-- 10% Monsters

Firstly it determines what faction will spawn (beastmen/chaos)
then if its chaos it randomly determines what god it will be, Khorne, Tzeentch, Nurgle, Slaanesh or Undivided.

Once that is known it then assigns custom UC buildings to the horde depending on what 'god' is selected.
(It's also dependant on what 'stage' the spawning is at-higher stage mean smore advanaced buildings)
(For example khorne hordes get khorne recruitment buildings)
This is so the horde can repopulate with the correct god units if damaged/units are killed.
This dosnt always happen because remember the AI can still build more buildings like the player if it has enough favour. (So a 'khorne' horde could for example construct the 'nurgle building' and therefore hire Nurgle troops.
(UC hordes have no upkeep if spawned via this script)

Then it will populate then horde, depending on what "stage" the game is at is what table it will spawn from.
(The end times tables have mroe elite troops, greater daemons etc)
Thsi process is mostly random, but certain armies are forced to contain certain units (x amount of Tzeentch warriors for a Tzeentch army for instance)

The latest version of the script will also generate a God aligned general correct to the army, (Khorne lord fo a Khorne army for example)
This is randomised too.
That means if it's spawnign a 'Tzeentch forece' It could be led by a Lord of Change, Tzeentch Sorceror Lord, or a Tzeentch Lord.
This is true for all gods.

Next the god aligned general will now be named drawn from a random name pool setup via the script.

The script also allows UC heroes to spawn when creating agents on the map.
It also changes the Sarothal Invasion to match the parameters above, with Sarothal himself being a completly custom Lord of Change.

Oh, just saw your other point, if you want to do that play Norsca, then it joins up with you.
It is possible to burn out the entire world (ive done it) but it does involve a good old bit of burning out recolonising AI.

Btw the Norscan scripts are heavily rewritten by UC too, allowing for god challengers and questlines that actually corrospond to the correct gods. (Nurgle challenger is a proper Nurgle lord with a Nurgle sorc etc etc)

Oh and if you really want to burn the world without it endlessly being recolonised...run a "AI does not colonise" mod alongside UC.

@Steelb_l_ade thanks for the details!! Good to know what all was done so I can better stay away from possible conflicting mods. Love the mod bro.