Warped Libraries

The Nether lacks a reason to stay for a while compared to The End and Overworld. Let's add a small boss to the library that could possibly drop something like Gate Stone Component that controls the warping. I'll let the Minecraft team handle the boss for it, otherwise everyone feel free to suggest below!

The Warped Library can spawn in Warped Forests only after a boundary from 0, 0 ,0 axis. The normal mobs of the library must include a form of Witch. The Warped Witches with faster and more variety of potions. On death they drop a random enchanted book and/or treasure map. PS. I look forward to seeing Warped Library designs below.

The boss? Like I said, I will leave it to you guys or the Minecraft team. But this boss will have 100% drop rate of Gate Stone Component. Only 1 of these bosses will exist per library.

The Gate Stone network to teleport to different places. But to take it outside of the library, you need Shulker Shells to keep its awesome power contained. When interacted with, it opens and gives existing Gate Stone locations to travel to. It cannot cross dimensions! Also, the player will have Warping Sickness after use for 2 minutes. This would not allow use of Gate Stone for 2 minutes.

Experience costs concept;
Overworld and The End per 600 blocks = 1 level
Nether per 100 blocks = 1 level

This concept is very end game content. Requiring massive amounts of experience and multiple Gate Stones to be useful. 

Have fun with brainstorming and building ideas!