Aight i got tons of ideas now for mods

@Goldorion a good thing for that is make endercrops! As it sits end stone is basically useless in vanilla minecraft, so make a new use for lets say, ghast tears + endstone + basic bonemeal crop (A bleached crop) that when combined can make an ender crop that grows in unique ways!

Hmmm, maybe an excavation totem that can remove everything from a medium area like 15x15?

Expand upon existing ideas, such as small quirks of the world and things of the like, example being making something like coal have some more variety to it's uses, or making a method of enhancing a useless item past it's current state, such as a chipped wooden tool, which does a very small amount of poison damage due to splinters or something lmao

Kinda basic, so i don't recommend things like that as it is an idea done millions of times over, however updating the end is kinda interesting. Make it so theres some more things to do there, bigger challenges. Maybe a corrupted end biome that has a hostile form of endermen that automatically attack you and as they walk around, the corruption spreads where they walk?

Something like that seems interesting lmao

I do like the drawback on the armor, where it's only useful during the night, and thus keeps diamond useful. Maybe make a mob similar to Phantoms, however they can be summoned via ritual during the nighttime, and they defend you? This should be possible without code, rituals are a thing that works really well for stuff like this.

Thats a, very very unoriginal idea. Sorry to be abrupt, but it's so so common. I mean thats the whole plot of Star Wars, the original and Sequel trilogy both followed that concept. I recommend rebranching, thats a nice title, so make it more focused on expanding the underground. May impliment some expansions on how you can use ores. If you'd like to use a magic style to it, make it so theres blocks that have mysical properties, like giving certain potion effects, or modifying/destroying blocks around it. These kinds of things aren't so common in mods, so i highly recommend adding something very unique like this. Maybe one of the refined ores could create a tool that can swap certain materials, such as lava into water, or gravel into sand. Another possibility is something that can spawn or create a custom mob, however the block is indestructable and spawns mystical creatures that drop custom drops exclusive to that ore, and is exceptionally rare, maybe make it only generate in the End for example. This would be a good way to expand upon the base mechanics of the game and fully flesh out a world in a new way!