That's more or less the definition I started with, with a side order of "The person who is willing to smack you upside the head and tell you to get over yourself and stop whining", as kind of the direct blackrom equivalent of a moirail. But I guess there's some canon that auspisticing is supposed to be a stable three-way relationship? Like it's not just you and your auspistice, it's one auspistice and two other people they are auspisticing for. Which is weird and asymmetrical but how it works. (Most of my Homestuck fic was actually ashen fic, so I have put probably too much thought into this?)