Paint Tool Sai :) If you don’t know what it is, I highly recommend looking it up!
These are my brush settings that I use the most:
Square brush - I used this one almost exclusively on the Naga Bites pictures. It has a hard edge and creates an interesting texture by swirling it about.
Paper brush - This is my ink tool. I turn off the watercolor texture depending on how clean I want it to be, but I usually leave it on for sketch like appearances.
Watercolor is my go-to brush for both sketching and coloring.
Soft is my blending brush.
Hope this answers your question. :)