Mythological roles

Each of the Homestuck Kids and the Trolls has a mythological role, as hinted at, during various points of the Homestuck story. All titles appear to consist of two components - a "class" and an "aspect." A title can be assembled from any combination of class and aspect - John in the kids' session is the Heir of Breath, while in the Trolls' session Tavros is the Page of Breath and Equius is the Heir of Void.

The term "HS 5528 (Hero)" can be used in lieu of the class when the speaker wishes to be generic, ie: John and Tavros are "Heroes of Breath". Both components of the title appear to have some mechanical effect on the game, although the precise nature of these mechanics has yet to be revealed, except for HS 5733 (two).

It appears Sburb may design planets with the titles in mind, as well as a secondary theme. The planets in the kids' session relate to their elements and associated items, and the ones in the Trolls' session relate to their personal interests.

Alternate Future Dave HS 03543 (said) that the game could not be finished with a dead Heir nor Witch, so these roles may be vital to completing the game, but this could have meant that the game cannot be beaten with any of the players dead. implies that every session will have a Hero of Time, and if the breeding duties are indeed linked to the Hero of Space they would be another constant in the game. Apart from this, the mechanical functions of the classes are unknown.

Classes

 * The Seer class fills one of the support roles in-game. True Seers, according to Word of, would not charge into the fray headlong but direct it as a conductor with a baton. They would sift through an infinitely-splitting mental map of every possible mistake made by their teammates and themselves, easily uncovering any gambits or malevolent desires and even imminent defeat due to a single grossly miscalculated and instinctive action as if they had the Official Prima Strategy Guide for Sburb imprinted deep in their mind.
 * The Knight class, as the name implies, serves as a protector for other players in the session. Dave (The Knight of Time) has so far saved the lives of every member of his team (resetting the timeline to save John and Jade, and then rescuing Rose from Diamond Droog at the end of act five, though whether she actually needed the help is debatable). Karkat (The Knight of Blood) is less successful in the role, despite his best efforts. He (very ineffectively) protects the unconscious Sollux during Gamzee's rampage, but he does manage to diffuse the Rare and Highly Dangerous 5x Showdown Combo, which would have doubtless killed one or more of his surviving friends.
 * The Knight may also have something to do with breeding the genesis frog, since in both sessions so far, the Knight has assisted the Hero of Space in the breeding - Karkat (the Knight of Blood) assisted Kanaya, and Dave (the Knight of Time) assisted Jade. However, this may be coincidence without correlation.
 * The Thief class is fairly self-explanatory. Vriska, as the Thief of Light, is able to steal luck (or fortune) from her allies or enemies, thereby making herself luckier. Thieves of other aspects would likely act similarly, turning the power of others against them.

Aspects

 * The Breath aspect seems to have some relationship to John's power over wind (such as The Windy Thing). It was never revealed whether Tavros has or could have had equivalent powers, but since he spent most of his time in the game asleep or otherwise passive, it seems unlikely that he was able to complete whatever makes those powers available. However, as shown Here, Tavros's breath appears as blue lines similar to the Breath symbol. The significance of this is currently unknown. The associated Denizen of the Breath aspect is Typheus, who presumably fills the role for all Breath players.
 * The Light aspect is equivalent to "fortune", and involves power over luck. At some point during their lives, both Vriska and Rose have the ability to see through solid objects, although Vriska's ability may be part of her troll biology, and Rose's power may be related to her role as a Seer. It has been speculated that Rose did not literally see through the magic cue ball, but that the scene was merely a visual representation of her prediction of the roll of the die contained within using her presumed "luck prediction" powers. The associated Denizen of the Light aspect is Cetus, who accordingly fills the role for all Light players.
 * The Time aspect is associated with the Timetables, time travel, and timeline maintenance in general. Heroes of Time are able to influence time without the use of timetables (or time music boxes), just as all players eventually learn that their powers are not dependent upon their alchemized equipment and that such props were never required. The player of Time also has a feature installed in their personal world in the incipisphere: a large structure that will obliterate the alpha and alternate timelines to rewind everything to before the game starts, as an attempt to have better starting conditions. The associated Denizen of the Time aspect is Hephaestus, who presumably fills the role for all Time players.
 * The Space aspect is associated with the player whose World contains their session's Forge. Both Kanaya and Jade live in Similar homes, next to a Frog Temple, and their dream selves are both awake before entering the session. Having their planet's First Guardian as a guardian is also a parallel (Jade was effectively raised by Bec while Kanaya was doc scratch's "protégé"), although Kanaya also had her Lusus for the majority of her life, and Jade's Grandpa died when she was still an infant. Beyond this, both players of Space have been in charge of the breeding of the genesis frog. How many of these similarities are coincidences and how many relate to the space aspect is anyone's guess. The associated Denizen of the Space aspect is Echidna, who accordingly fills the role for all Space players.
 * The Mind aspect is as yet associated with only one player, who also happens to be a seer. In this role, the Mind aspect's powers take the form of literally envisioning the aforementioned mental map of alternative possibilities (see Seer, above) manifesting as an HS 5734 (infinite net of flashing, teal synapses with images of each possibility inside each synapse). Even before playing sgrub, Terezi possessed the ability to manipulate and understand others, bending them to their will, although, this being paradox space, a causal relationship between this ability and her role as the Seer of Mind is impossible to establish and, as the two are ultimately indistinguishable, is something of a moot point.
 * From evidence presented in HS 6308 (this page), it would seem likely that the Life aspect is associated with an ability to heal oneself, and possibly others too. Given the reference to health stats in many videogames as 'life' and the measures available to replenish it, it would make sense that there can exist within Sburb some capacity to restore health (other than Vitality Gel). In this case, it may take the form of a player with restorative abilities. It would also seem to fit the general attitude of at least one of the players known to possess this aspect, as she so often champions "caring for the fit and unfirm". It would also seem to fit the story of her ancestor too, who had both a significant abundance of life and seemingly, an HS 5960 (ability to share it). The other player known to possess Life powers has apparently also managed to regenerate her Dream Self after it was coldly stabbed by the post-scratch Jack Noir.

Speculation
In HS 4467 (one of Karkat's memos), Kanaya speculates that Skaia assigns titles to players to challenge them, rather than to suit their strengths. This would certainly explain some of the apparent inversions, such as Rose being the Seer of Light despite her fascination with darkness and horror, and Jade's title as the Witch of Space despite her life never leaving her small island. However, her theory should be taken with a grain of salt, considering the titles of a lot of the players match them perfectly. It could be speculated that players are meant to "grow into" their roles; that is, when they first begin the session their title and its duties force them outside their comfort zone and seem very unsuited, but a fully realized Hero has matured into the role the game has assigned them.

Trivia
According to Andrew Hussie, other characters have also assumed these titles, or otherwise will when they ascend to the God Tiers.


 * Nicolas Cage is the Nick of Time
 * fedorafreak is the Gent of Piss
 * Andrew Hussie is the Huss of Lips
 * And, simultaneously, the Waste of Space.
 * Along with the Destroyer of Ships.