Key Holder Boss
Demon Eyes (three types)
Eye of Cthulu
Excalibur (different recipe)
Better Chests (obsidian chests)
6 non-terraria regular mobs
Mythril/Orichalcum and Cobalt/Palladium Nuggets
Sharp Swords (creative only)
Terra Beam (creative only)
Note: These features are for the newest version, not all versions
I suggest NEI of JEI for the crafting recipes, as there are lots. Click on an unopened door with a diamond sword to spawn the key holder boss. It drops a legend key, a vital ingredient for emerald+ tools.
These emerald tools are special, and use grass sticks (2 sticks, 2 seeds and legend shard makes 4) instead of regular. They are stronger than diamond.
Emerald boots are the best boots added in the mod, and get rid of fall damage. Emerald armor is crafted with a legend nugget. (9th of legend shard, 81st of legend key)