Mythological roles

Each of the Homestuck Kids has a mythological role, as hinted at, during various points of the Homestuck story:


 * John is the Heir of Breath
 * Rose is the Seer of Light
 * Dave is the Knight of Time
 * Jade is the Witch of Space

The Trolls bear similar titles to the kids.


 * Aradia is the Maid of Time
 * Tavros is the Page of Breath
 * Sollux is the Mage of Doom
 * Karkat is the Knight of Blood
 * Nepeta is the Rogue of Heart
 * Kanaya is the Sylph of Space
 * Terezi is the Seer of Mind
 * Vriska is the Thief of Light
 * Equius is the Heir of Void
 * Gamzee is the Bard of Rage
 * Eridan is the Prince of Hope
 * Feferi is the Witch of Life

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

Speculation
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.

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). At present, only the mechanical effects of a few aspects and those ones are known:


 * 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 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.
 * The Light aspect translates into "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.
 * The Time aspect is associated with the Timetables, time travel, and timeline maintenance in general. Evidently, players of Time are eventually able to influence time without the use of timetables (or time music boxes). 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 Space aspect may be 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, 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 Mind aspect goes hand-in-hand with the Seer class, if only because we've only seen one player with that class and aspect. Apparently, the Mind aspect boosts the stock powers of the Seer even more, the aforementioned mental map of alternative possibilities manifesting as an HS 5734 (infinite net of flashing, teal synapses with images of each possibility inside each synapse). Their powers will also apparently manifest before Sburb as an innate ability to manipulate and understand others, bending them to their will.

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.

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.