Minecraft – What bug is going on on the command

You can enchant books instead, which always puts only a single enchantment on it, and then use the book in the anvil to apply it to a tool or weapon. You do have to go through a lot of books to get exactly the enchantments you're looking for, and it costs extra to transfer the enchant from the book to the tool on the anvil, but what you get for the loss of efficiency is precision in having exactly the enchants you want.

Note that you can also combine enchanted books of the exact same level on the anvil to get one book that has that enchantment level +1. So, you can take two Efficienty III books, combine them, and get one Efficiency IV book as the result. In this way you can slowly gather together the pieces for your ideal set of magic tools and, with enough XP lying around to go through this XP-inefficient process, get a set of tools to your precise specs.

My thought is to use a structure block, to clone the entity.

So this is what I'd do it:

• First, spawn an armor stand (as a marker) in the location of the entity to be cloned.
• Move the entity to a predefined location.
• Clone it with the structure blocks.
• Then move the entity back to the marker, and the new one where you want it.
• Finally remove the marker.

I'll just show how to set up the structure blocks. I'll assume you know what your doing with the teleportation of the entities.

So the cloning device should look like this:

(The command block in the second picture removes the stone block when a red stone block is placed there.)

So the structure block on the left is the saving block, you place the entities to be cloned on top of it.

You must have "Include Entities" set to on, or it won't clone entities.

The block on the right loads the entities. (If you use red stone to save, it will only save to RAM, not your disk, which is good.)

(The structure name doesn't have to be "cloner", but it just has to be the same in both blocks.)

When you have the cloning device set up, you just have to teleport an entity on top of the structure block on the left, place a red stone block in place of the stone one, then one red stone tick later, you'll have two identical entities.

Necro edit: I though I'd clarify why there has to be a red stone tick between them, its because structure blocks are "slow" (compared to command blocks) and require time to save the structure data. A single red stone tick is simply easy to do, but it can be any amount of time, as long as it gives the structure blocks time to do their thing.