Views on the afterlife in Mystara
by RipvanwormerGaz 1: The Church of Karameikos teaches that a person's role in the afterlife depends on the amount of "stain" on their souls at the time of death. These stains are created by acts of assault, murder, abuse, lying, theft, adultery, living together before marriage, and not properly purifying oneself from these crimes. This stain can be erased by church-approved ceremonies and acts of self-sacrifice. The Church of Traladara considers only assault, abuse, murder, theft, and lying to be sins (they're more liberal on sexual impropriety) and a soul's position in the afterlife depend on their wisdom, strength of character, and good-will at the time of death rather than formal rituals of purification. The nature of the afterlife is unrevealed, but it seems evident that Thyatians and Traladarans both believe there are different positions for good and bad people.
Gaz 2: I don't see anything about the afterlife as such, but followers of the Eternal Truth are judged by their observance of various rituals.
Gaz 3: There are two kinds of imps: red imps and blue imps. Red imps serve Entropy and blue imps serve Matter. Red imps trick people into signing away their souls; these people cannot be resurrected unless the contract is found and destroyed, so obviously they have a very real impact on the character's afterlife. Blue imps seem to exist only to counter the schemes of the red imps and attempt to save the souls of red imp victims from damnation.
AC 9: The homunculi of this book (called familiars in the Mystara Monstrous Compendium Appendix) seem to roughly correspond to the imps of Gaz 3, but they're two feet tall instead of one foot tall and there are more kinds (AC 9 details three, while the MMCA adds another two to make one for each Sphere of Power). Using AC 9, ulzaqs would correspond to red imps and fylgars would correspond to blue imps, while gretches would either leave both sides alone or seek to banish the influence of both from the Prime Plane. Those who wonder why every sphere doesn't have its own kind of imp can replace the red and blue imps with aryths (Thought), bogans (Entropy), fylgars (Matter), gretches (Time), and ulzaqs (Energy), and any of the other imps could counter the schemes of the entropic bogans, attempting to steer mortals to their own spheres instead. The Gaz 3 explanation that imps are minor Immortal servitors who seek promotions makes more sense to me than the homunculus/familiar explanation that they're full-blown Immortals in disguise.
Dragon #158: Dragon spirits travel to the planes of the Sun, Moon, or Star Dragon, depending on their alignment. The most elect travel to the plane of the Great One instead. Dragon spirits resemble transparent, incorporeal versions of their living selves, but they can temporarily take on solid form once every 20 hours. Their memories of their former lives are hazy, unless they're reminded by visitors they knew when they were alive. They can be reincarnated.
Dragon #170: The dragon afterlife is a single outer plane similar to the Hollow World in structure, a hollow sphere filled with air with the sun in the middle. Dragon souls take the form of balls of elemental energy, with an elect few becoming "guardians" resembling their living selves. They inhabit layers of the plane corresponding to their color in life, not their alignment. They can be reincarnated.
Gaz 7: Valkyries bring the spirits of fallen Northman warriors to the plane of Asgard, where they battle each other and feast. The plane of Niflheim is the home of the Restless Dead, the shades of men, giants, and gods. They resemble zombies, and Hel tortures them.
PC 1: Faeries reincarnate.
Hollow World: This boxed set notes that Odin and Hel reincarnate good and evil souls.
Dragon #180: After a person dies, their soul travels to Limbo. The spirits there are solid and resemble their living selves, with all their equipment. Those with patron Immortals find gates leading to the home planes of their patrons. Depending on how faithful they were, they may spend anywhere from a few minutes to several decades in Limbo before being allowed into their patron's home plane. Thus, a member of the Church of Karameikos with "stain" on their soul would remain in Limbo longer than one who died purified and redeemed. For a member of the Church of Traladara, time in Limbo depends on a character's strength of character, wisdom, and good will. Followers of the Eternal Truth of Al-Kalim would spend less time in Limbo if they dutifully observed the Articles of Faith. By this system, characters who fails to live up to the tenets of their faith do not need to fear a Hell, only an extended time in Limbo. However, a character who worshiped an evil Immortal would end up in whatever hell their patron rules after serving their requisite time in Limbo. Those who betrayed their patron's philosophy are condemned to Limbo forever. Those who followed no philosophy in life must wander until they discover gates that lead to planes where free souls dwell - in the afterlife of free souls, spirits help maintain the cycle of the universe and the balance of the spheres. Prayers and rituals of the living can help guide souls to the appropriate gate. Limbo is also inhabited by fiends, minions of Chaos, masters of Chaos, archons, and undead.
Wrath of the Immortals: Five primary Outer Planes are described, one for each Sphere of Power. However, these aren't the only Outer Planes that exist. They include: Brynn (Matter), Draesten (Energy), Entrem (Time), Mirage (Thought), and Pyts (Entropy). Many Immortals have their own private pocket planes instead.
To summarize:
It isn't as simple as "good souls go to Heaven and bad souls go to Hell." It's more a matter of "faithful souls go to the Outer Planes and unfaithful souls stay in Limbo." Red imps, or the equivalent, can use their contracts to damn souls to whatever hell plane they're native to (probably Pyts). In the faith of the Northern Reaches, souls (after their time in Limbo) go to either Asgard or Niflheim depending on whether or not they died in combat. Dragon souls, after a time in Limbo, either travel to a communal dragon plane or the plane of the appropriate Dragon Ruler, depending on which version you believe. Free souls have their own afterlife, unaligned with any particular Sphere. Followers of the Immortals travel to the realms of their patron Immortals. For followers of multiple Immortals, there must be some system to sort out who goes where, or allied Immortals might maintain shared afterlives. Immortals may elect to reincarnate souls in their care back to the Prime Plane in new bodies, transform them into servitor beings, or let them do whatever they want. Perhaps some of them are transformed into imps/homunculi/familiars to prove themselves before achieving greater positions.