Caliborn

undyingUmbrage is a cherub with HS 6862 (cherry red blood) from an unknown session of the game.

uu's symbol is a variant of the astrological symbol for Ophiuchus, different from Calliope's (albeit the more traditional one). Unlike all previously revealed symbols (except Calliope's), his symbol contains two colors, a dark grey "U" with a red tilde (~) across it. He seems to be the mentioned "brother" Calliope is working with, and is generally an antithesis of her. He appears to be ornery (which contrasts Calliope's politeness). uu's typing quirk is also the opposite of Calliope's, capitalizing every letter except u. Like Karkat and Calliope, he types in a shade of grey, having abolished "hemotyping" as part of a game he has been playing with Calliope for most of his life.

He is allegedly a Derse dreamer, due to Calliope mentioning that she is a Prospit dreamer and that her brother must enjoy his "Netherworldly affiliation."

According to uu, the cherubs have a sort of superstition involving Lil' Cal, which suggests that any person close to or even occupying the same plane of existence as Cal, or any "jujus" like it will have a nightmarish life. This superstition probably has to do with another character who has many of the same features as Lil' Cal. Apparently the fear associated with this superstition isn't debilitating however. The use of the term "juju" might also imply he recognizes Cal's origin as a Subjugglator-created Chucklevoodoo.

Personality
uu is perhaps the most alien of all the voiced characters. He has a terrifying obsession with playing games, so much so that Calliope claims his love for them surpasses human comprehension of what love is. Additionally, he is obsessed with superstitions and "jUjUs", which define much of the relationship and "game" with his sister. Thirdly, he seems interested about relationships, but unlike Calliope, he sees them as disgusting and pornographic.

Despite this obsession, he is apathetic towards Sburb, seeing it mostly as a means of escaping his dead home planet. He still intends to play it, but he plans to treat the game as a competition against Calliope instead of the cooperative game it is meant to be, which could make winning the session impossible.

Despite his cartoon villain spiel and bizarre hobbies, uu can be quite clever. He enjoys deploying "shitty" twists to spoil his "opponent's" game (such as pretending to switch positions of two chess pieces but merely camouflaging them as each other), and could be quite threatening if he was not so obsessed with theater.

Relationships
He is the "brother" of Calliope and has a conflicted, aggressive relationship with her. He often threatened to kill her dreamself, an act he HS 6875 (eventually performs) by hiring his Session's Jack Noir, who then stabbed her. In addition to the larger game between him and Calliope, the two regularly play chess, with Calliope winning every game except one.

He seems to have a liking for Dirk, as far as he is capable of such emotions, calling him the most tolerable out of the B2 kids. It should be noted that, so far we have yet to see uu interact with any of the kids but Dirk. He also played a game with Dirk Strider in which he threatened to kill Calliope's dream self unless Dirk drew him pictures of the B2 kids in various romantic pairings. When Dirk won by making him too uncomfortable to keep playing, uu revealed that he had HS 6874 (already killed) Calliope's dream self before he started the game with Dirk.

Role in Society
uu is the antithesis of Calliope, who, in turn, is an antithesis of Karkat. This implies further association with Karkat (except while Karkat hates mostly himself, uu hates everything else). His ornery nature, tendency to ramble, his typing quirk, and their shared blood color all support a possible connection to Karkat.

A common theory is that Calliope and uu are two halves of one body, in a relationship somewhat akin to Jekyll and Hyde, with one being the exact opposite or yin to the other's yang like in the cancer symbol (Calliope said she had to go to sleep and then uu became active). This is further supported by Calliope's conversation with Jane in LOCAH, when Calliope states that after a "dreadfUl nap" she "woke Up to find [her] coplayer has made a terrible mess here." This prompts a string of questions from Jane which Calliope is uncomfortable with, including whether or not she and uu have met. Also notable is the fact that Calliope and uu seem to be incapable of simultaneously cheering/jeering one another. They also appear to be playing chess together on one board, and yet are only able to infer, rather than observe, one another's actions (such as Calliope suspecting that uu is HS 6932 (possibly eating the chesspieces)).

Role in the game/Connections to
uu has been confirmed as a Hero of Time, one of two essential aspects to a session, along with Calliope as the Muse of Space. Since Calliope and uu have two previously unrevealed master classes, uu's actual class is currently unknown. It is revealed by Calliope to be the most active class, and reserved for male players. Calliope's reluctance to reveal her brother's class, coupled with the fact that their species looks like, suggests that uu may be the Lord of Time and may in fact be a young version of English himself. Another indicator for that could be the color of English's cheeks. Calliope's cheeks have the same color as her blood and eyes, which might suggest that a cherub's eye and cheek color fill in with the pigment of their blood like troll's eyes do. This would mean that shares uu's rare mutated blood color.

Calmasis
Continued revelations concerning the Complacency of the Learned books suggest that Calliope and uu are two parts of the same being. In Dirk's conversation with Jake in 2008, the discussion of the books brings up an image of Calmasis bound by two shackles, one bearing the Calliope's Caduceus sign standing on red ground and the other bearing the lesser-known Ophiuchus symbol of uu on green ground. It should be noted that the more common Ophiuchus symbol is often confused with the Caduceus symbol. Andrew Hussie may have been using this to imply that they are represented by the same astrological sign, which happens to be the 13th sign of the Zodiac in some cultures, which adds to the theory that the two cherubs are one. In this picture he/she appears to have a particular deudly firearm, leading to speculation that uu/Calliope may be Lord English's ultimate downfall.

Connections to Saw
Many aspects of uu appear to be related to the Jigsaw Killer from the movie series Saw. Both force people into playing their games (with uu's greeting "I want to play a game" reminiscent of how Jigsaw greets his victims), use a black and red color scheme, and unveil twists that undo any progress or reward a "player" might achieve at the end. uu may also bear a resemblance to Jigsaw's puppet Billy, as he was revealed to be a cherub like Calliope. This race was HS 6997 (shown) to have blood-colored spirals on their cheeks and have a puppet-like appearance. Billy was a puppet with red spirals on his cheeks, so the red-blooded uu should bear the same markings.

While not actually part of the Saw movies, uu's requests for pornography do have a connection to them; in a famous MSPA Forums thread entitled "Cheerfulbear - PLAY ME", a user adopting the identity of Jigsaw demanded that Andrew Hussie draw him Muppet Babies porn.

Trivia

 * uu's hex code is #323232, 32 being the atomic number of element Germanium, a brittle grey crystalline element used as a semiconductor and anemia treatment. 3 is the difference of 9 and 6 (Karkat's hex code is #626262; Calliope's is #929292). In addition, 6 and 9 are both multiples of 3.
 * The word Umbrage can mean an offense or an annoyance. It can also refer to a shadow, likely a nod to the Umbra portion of uranianUmbra.
 * uu's symbol is the symbol for Ophiuchus proposed by British astrologer Walter Berg in 1995, which gained widespread popularity in Japan, whereas Calliope's symbol is a hybrid of Caduceus and the rod of Asclepius.
 * The red in said symbol matches his blood color which is the same as Karkat's blood color.
 * uu "jeers" instead of "cheers", opposite to Calliope.
 * uu seems to represent different aspects of the Homestuck consumer community from Calliope, particularly his impatience with the speed at which things unfold. As many less fanatic readers do, he complains about long pesterlogs formatted strangely in unusual colors. Calliope's relationship with him mirrors the fans who keep pestering their friends to read Homestuck, even though they're not interested or don't "get" the story.
 * uu's "tumut" emote is one letter from "tumult", which means chaos or disorder, possibly a reference to his rather aggressive personality as well as his handle.
 * uu is the only character in Homestuck to have lowercase for the initials of his screen name.
 * He has also been HS 6880 (shown) to have HS 6972 (slips of tongue) much like Karkat when using HS 5771 (figures of speech).