What is, in your opinion, the least-explored or least-represented Aspect in Homestuck? I'd say Blood personally. I mean, I can understand what the aspect means in a general sense, but I feel due to its inevitable nature of being the "relationships and blood bonds" aspect, its one we will just never see some of the other potential usages of.

I would say Karkat is featured as a rather prominent Hero of Blood with a lot of ties to Blood and actual talk about what Blood meant for him and what it turned out to be for him and his role and purpose. I would say Doom may be the least explored one, character-wise at least.