I love the idea, it reminds me of Hades by Supergiant, where every god has their own mechanics you can identify them by! I think it needs to be clearer what each effect does though, I have not felt a difference for most of the time.
Also a thing to think about: Why would I use my sword if the sling is better in any way? Think about the decision the player has to make to choose which weapon to use and how to make that choice interesting!