Ok nevermind, turns out I just have to read more carefully, I did not use draw gui for this,
haha. No worries! Yeah, its just a standard shader protocol. So you can even use Horrifi on individual sprites if you wanted! The GUI just makes it so that you an apply it to the entirety of the application surface. You could also set it as a 'layer script begin/end' for the layer you have all of your instances being drawn if you want as well. Totally up to you! :D I am glad you figured it out! :)