Well, I didn't update this thread in a long time. So here's a big update post!
I've been very busy IRL lately, but I plan on releasing a 1.0 content version of EMM when TML 1.4 is out on Steam.
Here are the outlines of the current content plans so you get an idea:
Quick introductory
EMM essentially 'expands' vanilla prefixes by adding its own system that modifies items. It allows items to grow in power and get special effects, up to 4 effects maximum per item. (you can also still have prefixes) EMM's goal is to enhance the vanilla item customization and access item scaling beyond Moon Lord progression to transition into post vanilla mod content.
How it works
EMM tries to be present throughout your entire playthrough. Your access to rerolling modifiers will grow as you progress. Firstly, items crafted and drops have a random chance to come with some modifiers. Naturally spawned modifiers will never be more than 2 effects maximum. Modifiers that roll have their own internal 'stats'. They roll randomly, so each effect has its own unique effectiveness/power. For example: 1-10% more damage How powerful these can roll will progress over time as you get access to more and new ways of modifying items.
Crafting
There are 2 main methods of crafting/modifying items: cubing and essence crafting. Using cubes will be your primary method of rolling items and getting the most powerful rolls. There are many different kind of cubes you can collect that each have their own uniqueness in how they roll and what they can roll. Essences are unique in the sense that they have an 'embedded' power which will always be granted upon the item. Essentially essences can be used to target farm specific powers.
UI
The crafting menu is accessed through EMM's special crafting bench. Place the tile anywhere and right click it to open the UI.
Cubing
Cubes are the primary method of getting the most powerful effects and rolls. They are consumed upon use and there will be multiple methods of collecting them (random drop, craft etc.) There will be many different cubes to collect as well as themed cubes (hell cube, jungle cube etc.)
Essences
Essences will make target farming specific mods easier. They will be random drops throughout the world (monster drop, found in generated chests etc.) as well as dropping from bosses and events (for example blood essences from blood moon) Essences can drop in varying tiers, from tier 1 through 5. The higher the tier the better powers you will get.
Soulforging
Soulforging is a third system that comes into play a bit later in the game. It is dual-purposed: enchant your weapons with very strong powers and increase stat scaling on any item! Firstly, the main concept is that (for now) weapons can be enchanted with powerful souls. They then get a very special effect, that makes the weapon more unique and powerful. The effects change based on the type of weapon and type of soul used etc. Souls will primarily drop from bosses, e.g. Plantera Soul / Jungle Soul. Soulforging also plays in end-game as a means to effectively 'infinitely' scale item stats. You can spend soul essence to upgrade an item's soul influence tier, each tier increasing the item's stats/rolls. The further you go into the system the more essence you have to spend to upgrade the item. For early game, there is a rare chance your crafted items and monster drops can drop with soul influence. Essentially that means if you find a soul influenced items, anything rolled on that item will have higher stats. Having good modifiers on an item and then upgrading it through soulforging will be your end-game method of scaling an item's power. The primary goal of it is to scale items beyond Moon Lord, for example if you play with mods that add content past the final vanilla progression.
End-game upgrades
If using cubes or essences wasn't enough, you can combine an essence with a cube to create an essence influenced cube. This special type of cube grants access to new pools of modifiers you can roll that are normally inaccessible! These cubes can roll new unique powers that are exclusive to the essence you combine the cube with.
Cross mod content and variety One of my major goals with EMM has always been to promote cross mod content.
This is why other mods can add their own modifiers, rarities, cubes, essences and so forth!
You heard that right. The idea is that other mods can add their own unique content, if you play their mod with EMM.
Obtaining cubes
When you gather a cube for the first time, you unlock it's 'recipe' and you can now craft the cube using soulforging More powerful cubes will cost more essence to craft.