High Trade Villgers

High trade librarian, the high trade librarian would have the best trades in the game but very hard to find. They would be found in zombie dungeons and locked up in a cage.  The villagers would trade:

Diamonds -> Emeralds

Emeralds-> Diamonds

5 books and 30 emeralds-> Mending

Etc.

It can have OP items like: GOD apples Netherite, Diamonds enchanted books, etc and maybe just meh items like gapples, iron, coal.