^ That's not because they don't want you to have these items. The game's Engine is Lua-based, whereas all the major entities (OBJECTS actually) in the game (Kratos, Atreus, Sindri, etc.) are Lua virtual machines. In their contexts there's a Lua state being created. In this state are the corresponding functions being run, performing a series of operations (SUBOBJECTS). The functions execute Lua bytecode. Much like UnrealScript, these are precompiled scripts (which I was able to decompile and see what they do; will post them later when I have a complete list) in the form of bytecode tokens, where each token represents a certain instruction a Lua VM is capable of interpreting. Based on the conversion, a core Lua function is executed in its place; of course, with proper arguments.
Now, all the mumbo jumbo aside, you can't keep the item because another unlock is required (e.g.: defeating some boss or completing a challenge). These unlocks should also be in the big ass table I've provided, waiting to be discovered. Before its current form, I only had the hashes, not even the internal names. Then I figured out how to hash names, which led to completing 99.9% of the 4th column. The reason I went to the struggle of getting the
Internal Names was so they'd HINT at what they could unlock. I completed 10% of the list aiming in the dark, just testing hashes, one after another. No names to guide me. Now you have the internal names, so make use of them to get to what you want.
An example are some Light or Heavy Runic Attacks which I could unlock, but when I went to Inventory, they weren't there. Why? Cuz apparently they are Blade attacks. And I don't have the Blades unlocked at his point in time. Once you unlock them, those gains work just fine. Moral of the story: keep testing
As well as apply some common sense and logic. The game is made by human beings, therefore you too can predict from all these variables thrown at you how this shit would work in theory