The "Magic Slots Function" adds four magical items (Amulets, Runes, Rings, and Gauntlets) as well as slots to place those items in. In order to gain one of those items the player must defeat a sort of "guardian": a Wizard, an Elf, a Paladin, or a Dwarf.
This map is meant as a demonstration for the function, as well as to provide a way to move the function to another world.
There is a resource pack attached to this function, if you're interested. It works fine without it, but the resource pack definitely makes it look a lot cooler. :P
https://minecraft.curseforge.com/projects/magic-slots-function-resource-pack
If you want a sort of demo as to how this function works, check this video out.
https://www.youtube.com/watch?v=njBJ7Hu7KE4&feature=youtu.be