Below is a link to the full item list FAQ I've been working on these last couple of weeks.
Click me to go download the list
From what I can remember over the course of the runs this list is pretty accurate but with how many items there are across all the modes and the fact I have the memory of someone ten times my age I don't doubt I have made an error somewhere.
If you look at the list and notice any mistakes then please let me know in this thread and I will update it. The list contains all fiend challenge rewards too but not scarabs as they have their own thread.
The last thing I need to do is go through Ninja Dog and add in where you get the bands which I'll do on a stream this weekend and then hopefully it's all finished.
Item Locations for Story Mode - All Difficulties (work in progress)
Moderator: TheGodfatherDictator