This is a survival-based datapack that aims to expand the usual minecraft experience. It contains a lot of new items, weapons, food and even several bosses. There are new tiers of items which go beyond diamond andd require booses to have been defeated. To make the game a little more challenging and also to be able to introduce better armor, the already existing armor sets have been nerfed.
This data pack also includes a new custom structure generation, which hopefully works. You can find loot in those structures, but they are not required to progress in the game in any way.
Also included are custom crafting stations as well as "altars" for rituals.
The data pack includes a complete guide to it, so you should be able to use all of its features. It is located in the data pack file and is called "guide".