Copy item into custom item based on tag (1.19.2)

[Silvertide]

I am adding an item to a new tag group I created and I wanted to see if there was a way I could loop through all of the items in that tag group and modify them or create a new version of them.

For instance, I add "minecraft:diamond_sword" to the tag group. My mod will scan all items with that tag and create a new custom item that is a copy of that item. That way both the vanilla diamond sword and the custom diamond sword with additional features will exist in the game.

I am not sure on the best way to do this. I was looking at RegisterEvent and possibly registering it there. Does anyone have any suggestions on the cleanest way to do this? I would also need to make sure this mod loads after other mods so that it could access items from the other mods and create copies of them as well.

Any help is appreciated!

Edited April 3 by Silvertide
clarity

[ChampionAsh5357]

Why are you trying to copy the item and make a new version?

[Silvertide]

I want to allow that original item to exist in the game, but I want to create another upgraded version of it with extra functionality.

[ChampionAsh5357]

Why not attach a capability to the ItemStack instead? Is there some reason it needs to be a separate item?