Rather than increasing "world gen", Reliquary can accomplish recipe tiering and improved recipes by adding some diversity to the loot list of most (if not all) hostile mobs. The items will [hopefully] allow for uniquely Reliquary recipes that have more flavor than just "void tear + stuff" and "put lots of potions in it".

This is especially important since Reliquary will be moving away from hard coded potions, and thus will not have the luxury of using them [easily] in recipes. Besides they're boring.

(note that every single one of these is potentially an excellent candidate for being a new potion ingredient in the proposed apothecary system we're designing, in addition to the mob's standard drops)

Here's the planned list thus far:

Spider/Cave Spider - Chelicerae - A pair of spider mouthparts, used in recipes where poison or debuffs might be a factor, as well as a future apothecary ingredient. Cave spiders have a higher drop rate.

Skeleton - Rib Bone - A smooth pointy rib bone, it will function similar to the regular bone drop, to create bonemeal. It will have a higher rarity due to its ability to be used in certain recipes.

Wither Skeleton - Withered Rib - Used in crafting wither-based components or in anything dealing primarily with death and decay.

Zombie/Pigmen - Zombie Heart - What's left of it, used for a series of inspired mob-ignorance items, it is the core component for making the set of items that cause certain monsters to ignore you when carried. It will also be an ingredient for certain [vanilla-unobtainable] debuffs. Zombie Pigmen have a higher drop rate.

Slime - Slime Pearl - A black beady thing that was probably an eyeball. The Slime Pearl is going to be a rare drop for tiering purposes in recipes, mainly. It will probably make its way into several existing recipes.

Blaze/Magma Cube - Infernal Core - The flaming core of its respective owner. These are going to be extremely rare, when intact, and vital to the production of fire-based items and sub-materials.

Ghasts/Creepers - Catalyzing Gland - The source of these explosive creatures' powers. Used in creating explosive things, exclusively. Ghasts have a slightly higher probability of dropping one.

Enderman - Nebulous Heart - An inky black heart that swirls with dimensional energy. It's used in creating items concerned with teleportation, darkness and "infinity".

Bats - Bat Wing - Bat Wings are used in recipes where mobility is a factor, such as the Angelic Feather, or Haste Potions.

With these and existing items, tiered/multi-layered recipes can be created to achieve a more diverse recipe list, give it better flow, and hopefully improve the look and feel of the mod in the process.

Some of these descriptions are now invalid, I did my own thing on the sprites.

These are done. Also added "Frozen Core" to Snow Golems, and 'Eye of the Storm' to charged (!) creepers