>>150203867
Blood is connections, friendship, bonds (probably literal too like chemical bonds), stuff like that. Karkat is the Knight of Blood, basically weaponizing friendship. Basically being a leader, he was able to unify his team and even in current day Candy he is the best leader for the world. Kankri on the other hand (more specifically the Signless) is the Seer of Blood, he sees the faults in society and in Signless' case he saw visions of his counterpart's life.
Life is, well, life, energy, fertility but also optimism and potential. We don't have the best examples of Life since all our examples either don't do anything or have to do with the lack of life. Meenah/Condy of course takes life, both in the sense of her society but also literally stealing it to make herself or her pawns live longer but she also stole Nanna's potential (Nanna says so). Something similar happens with Jane, who is raised by Condy to be an heiress, removing her self-actualization. Jane sees her own role of Maid of Life (someone who serves their aspects goal) within that crocker empire role as "I have to make a bunch of babies". Feferi doesn't do much so uhhh moving on
Doom is.. uhhh... well... it's the opposite of Life, that's for sure. It's,.. green. Yeah, we only have two examples and neither of them do shit. But based on Life we can make some assumptions. Where Life is optimism, Doom is pessimism. I think there's some fate aspect to it, with Sollux being tied to the inevitability of destruction through sgrub plus his own tendency to hear ghosts (his Mage of Doom role). Ultimately we don't know much. Though this will probably change soon with Act 2 of HSBC having started and one of the kids presumably being a Doom player (my guess is Tavvy being the Bard of Doom)