These materials you require are acquired in various ways. The fast way is by hunting. The other method is by using a Targeting Module, which I have already mentioned as something you can craft. I will cover both methods now.

The Targeting Module

This device is capable of many things. Its first function is the capability of tracking strange sources of energy that is emitted from what are described as "Phantom Items." If you have enough power in one of these, you can overcharge it and it will lock on to various items that your enemies are holding, which you can then take from them.

The items this device has been noted to find thus far is:

Poisoned Tip

Keep in mind there is no way to select what the module locks onto. And I am not sure how it determines which of these items to lock onto.