Upgrade System in progress

I'm making a upgrade system to could have some slight customization ingame. I want this system don't become neccesary to advance the game or really powerful, I want make it like a slight help and to orient it to your playstyle. 

Some enemies or places will drop light dust and with that item you will be able to choose various passive talents that will help you. But this system will be restrictive, if you have skills in a tree you can't have the last skills in another tree making an election what tree you want.

This probably will need balancing and testing cause I don't want overpowered skills or needed skills