What's the deal with Brain Ghost Dirk? I don't really understand his nature (may just be from not understanding aspects too well.) Also I know for some time John and Dave had <3< and <3 shirts, did Rose and Jade ever have <> or c3< shirts or are those quadrants not important enough in this context?

We never saw them with <> or c3< but they could’ve easily had them in the past, maybe Jade with <> and Rose with c3<? As for Brain Ghost Dirk, he’s a bizarre mix of Jake’s Hope and Dirk’s Heart. See, Jake, as a Page, and specially a Page of Hope, made a projection of his subconscious in a way that seemed reliable and good for him, much like Tavros has Rufio, Jake has Brain Ghost Dirk. Except of course Dirk’s existence is weird as fuck because he’s a Heart Player and has like a Zillion splinters, so even this one sort of counted as part Dirk, even though it’s Jake’s Subconscious Mind, it acts as a sort of Projection of what Jake sees in Dirk.