I know personally I have been struggling on finding free blending brushes for procreate so I found a bunch and made a few more
I have compiled all these brushes in one set
However I only made the Classic Sai Water brush and the Water but not as good brush based of the Classic Sai Water brush in Paint Storm the rest of the brushes were created by other people for use to use for free and I do not claim them as my own
https://www.dropbox.com/s/j26zmaczysct80b/Blending_Brushes_.brushset?dl=0