I found it, by accident, while searching for a different web comic entirely, called
"Ethos".
Ethos has some uncanny similarity with twokinds, which is why when I first stumbled across twokinds, I thought I had found Ethos for a little while.
The general plot to the other comic largely revolves around the human race alternately annihilating or enslaving a race of cat people.
Similar enough that it can be best summed up by saying "Twokinds, but replace all the humour and boobs with horrific violence".
For instance, there's a rather disturbing scene where a large burly man is beating the [censored] out of one of the male cat people, all the while calmly explaining the technical details of why he's beating the poor thing into a bleeding lump.
The scene ends with a very young child (kitten, technically, I suppose) getting blood splatter on his cheek.
Anyway, so that's how I first got here.