Because they are dark-matter dominated, dwarf galaxies provide some of the most stringent tests of our cold dark matter model. We continue to debate whether the number densities and distributions of low-mass galaxies match theoretical expectations. I will describe how the advent of deep and wide-area surveys like the Hyper-Suprime Camera (HSC) Survey (and eventually LSST) are changing our ability to find and characterize low-mass, low surface-brightness populations. First, I will present a new calibration of surface-brightness fluctuations to the blue, which will provide a powerful new tool to determine satellite luminosity functions around nearby galaxies. Second, I will talk about our ongoing search for low-surface brightness galaxies is all environments with the HSC survey. Finally, if time permits, I will discuss the massive black hole populations in low-mass galaxies.