in circumstances like this we might be logically expected to take the route of assuming that there is no defined soul in Homestuck and, just like in real life, we’re expected to philosophise over the meaning of the soul for ourselves. but we can’t begin to understand Dirk’s role as a prince of souls without this basic foundation…

the main clue would seem to be in Dirk’s enthusiasm for Plato, who had a very clear idea of what the soul was; but Plato’s soul was the invincible idea, which in Homestuck is called the ultimate self. and Book 6 has already given us that clue that in the dream bubbles, “memory of someone [is] linked to the truth of that person’s existence”. so we come back around to soul-as-memory.