mythological roles

Blood - Allegiance, connection, literal blood
Breath - Wind, Animation, Movement
Doom - Death, doomed timelines, bad luck
Heart - Souls, The Self, sacrifice
Hope - Hope, Light, success
Life - Life Force, Nature, Creation
Light - Fortune, Knowledge, Literal Light
Mind - Thoughts, Decisions, Communication
Rage - Anger, Strength, Madness
Space - Size, Location, Mass
Time - Duration, Causation, Paradox
Void - Absence, Nothingness, Obfuscation, the Void (beyond the Furthest Ring)

Seer - Sensing the aspect; Sensing the group's connection to the aspect
Knight - Harnessing the aspect; Using the aspect to protect the group
Rogue - Stealing or destroying the aspect to aid the group
Thief - Stealing the aspect for personal gain
Bard - Removing the aspect; Allowing the aspect to use oneself to destroy
Prince - Destroying the aspect; Harnessing the literal aspect to destroy
Sylph - Using the aspect to heal the group
Witch - Manipulating the aspect's traits without creation or destruction
Maid - Providing the aspect as a resource for the group; Drawing on an infinite supply of the aspect
Page - ???? (probably aiding the knight in a more active role)
Mage - Is immune to their aspect, understanding their aspect, granting their aspect to others
Heir - Protecting oneself with the aspect; Harnessing the aspect as a tool (not only a weapon, and not altering or creating the aspect itself)

For example, Maid of Void, to take a random example, might either be an useless shit that can offer nothing to the group or might be able to offer peace with the horrorterrors and passage through the Void, and would be able to grant themselves absence- Of hostiles when alone, or of debuffs. Another example- Witch of Light could alter what actions/things were or were not lucky, and could make it very light or completely dark. Yet another, an Heir of Void would be extremely proficient in unarmed/unarmoured combat, obfuscating their existence and using their bare hands as a tool to build and fix- Equius confirms this.

A more complete- if not definitive- list (got bored and stopped filling it out halfway, you get the idea):

SEER
Blood: Looking to past/future lives for guidance; Finding the way out of infighting
Breath: Seeing the direction of the wind; Predicting weather; Sensing breathing things
Doom: Foreknowledge of decisions that will doom the timeline; "seeing" (assuring) the method by which something will die
Heart: Reading thoughts and emotions; Sensing pulses
Hope: Foreknowledge of decisions which can save an otherwise doomed session; Seeing the "silver lining" in a situation (boosting morale)
Life: Detecting life; Seeing what will keep a being alive the longest; Seeing into an organism's past
Light: Seeing the path to fortune (the best outcome); Seeing actual light (akin to breath's first power)
Mind: Seeing the results of actions and intentions; Knowing what to say to control another's mind
Rage: Foreseeing the path to victory and glory in battle
Space: Looking into any point within the Furthest Ring
Time: Knowing which timelines are and are not doomed; Knowing what happens before and after the session
Void: Communion with the Horrorterrors; Looking into other sessions; Looking past blackouts

KNIGHT
Blood: Protecting his fellows from death; Corrupting enemies' blood
Breath: Using the wind as a direct physical weapon; Making shields of air; Forcing breath into the recently-deceased
Doom: Cursing enemies; preventing doomed timelines
Heart: Buffing allies; Self-sacrifice to save others; Attacking or changing an enemy's personality itself
Hope: Allowing allies to continue fighting after their attributes have dropped to 0 (or lower); removing debuffs
Life: Directly attacking an enemy's life force (ignoring armour or buffs), healing allies
Light: Giving allies luck; Avoiding tragedy; Blinding foes
Mind: Attacking an opponent's psyche (fear effects?); Fortifying allies' minds; Allowing communication beyond the language barrier/afterlife
Rage: Berserker; Avenging allies without failure
Space: Warping the enemy's mass to make them implode or dissipate; Teleporting allies
Time: Reversing poor decisions; Stacking attacks; Exploiting time loops
Void: Blacking out allies; Using void(s) as a weapon; Moving foes to a void; Summoning ghosts temporarily

ROGUE
Blood: Strengthening bonds between players; Destroying enemies' allegiances
Breath: Asphyxiating enemies that need air; Providing safe travel through voids
Doom: Outfitting their team with items they could have but did not alchemit
Heart: Allowing teammates to take on the shapes and abilities of enemies
Hope: Destroying enemy morale; Increasing ally morale
Life: Absorbing health from enemies; Healing all allies
Light: Destroying enemies' luck; Increasing the luck of their teammates
Mind: Allowing teammates to duplicate the actions or abilities of enemies; Stealing enemy intelligence
Rage: Calming enemies; giving allies additional attacking power and vigor
Space: Moving mass from one object to another; Increasing or decreasing distances between objectives to aid the team
Time: Eliminating the possibility of doomed timelines to postpone the Reckoning
Void: Stealing knowledge from Horrorterrors and other sessions to aid their team; Blacking out their session; Traversing the Void personally

THIEF
Blood:
Breath:
Doom:
Heart: Taking on allies' damage; Stealing souls of the dead to use as MP
Hope: Stealing the advantage in an encounter
Life: Absorbing health
Light: Stealing luck
Mind:
Rage:
Space:
Time:
Void:

PRINCE
Blood: Destroying allegiances; Rallying allies; casting from health to create streams of blood to crush and drown large groups of enemies
Breath:
Doom: Destroys feelings of
Heart: Destroying ego; casting a beam that destroys curses and hostile entities
Hope: Crushing hope; Creating a wafting beam of white light that burns through all it touches
Life: Attacking life force directly; Casting from health for an extremely powerful beam attack
Light: Making the situation as completely unfavourable as possible; Firing a powerful laser beam
Mind: Erasing targets' sanity; Erasing thoughts (might allow shenanigans like invisibility); Casting a beam which affects only sane opponents
Rage: Releasing tensions and calming anger; Casting an extremely powerful, unaimed explosion
Space: Collapsing the distance between any two points to nothing; Opening pocket universes; Destroying corporeal forms
Time: Destroying stable time loops without creating doomed timelines; Rapidly aging enemies
Void: Discovering the unknown; Erasing things from existence