Shadowthrone (aka Waylander, aka Dakeiras)

Alignment: Chaotic Evil
Holy Symbol: Twin Daggers against a Shadow Tower
Portfolio: Death, Assassins

5E Domains: Death

Once known as the hero Waylander, and a follower of the Raven Queen, Shadowthrone thwarthed Orcus' plans to kill the Raven Queen, and stole the power of Death from her. Helped by the Spider Queen, he escaped the wrath of the other Gods, and ascended to Godhood.

He's currently a prisoner inside the sword Blackrazor, wielded by the warlock Tarlyn. (see here).

The Oracle

Alignment: Unaligned
Holy Symbol: An androginous white face.
Portfolio: Knowledge, Prophecy.

4E PHB Equivalent: Ioun

5E Domains: Knowledge

Deep into the Dragonlands, a huge blue stone, streaked with white, fell from the sky. Around this impressive landmark, a town grew, is inhabitants called by weird voices in their minds. One day, a door opened into the stone, and those brave enough decided to step into that door. Inside, they found the Oracle. The Oracle appears as an amourphous mass of faces and eyes, coming out of a bottomless pit inside the Blue Stone. The Oracle seems to have the power of Omnisciency, knowing Past, Present, and Future, and discloses its secret to the great heroes of Tyrrah.
Naturally, a Mistery Cult was soon born from te devotion to this entity.

Oneiros, the Eternal Riddle

Alignment: Unaligned
Holy Symbol: A Scroll with Mysterious Runes
Portfolio: Trickery, Illusion, Dream, Love.

4E PHB Equivalent: Sehanine

5E Domains: Trickery

Into the Silent Desert, an ancient ruin arose from the shifting sands. In the ruins, a scroll was found, and on that scroll was written the Eternal Riddle. The first prophet of Oneiros claimed to have deciphered the Riddle, but the ancient language of the papyrus has been lost to Men. All those that try to decipher it, turn mad, or are forever lost in the Illusion of Truth.

No one knows if Oneiros is the name of the ancient ruins, of the prophet, or of a divine power. All that it is known, or actually, believed, is that Life is Illusion, and Dreams are the shaped Reality.

The Winter Queen

Alignment: Unaligned
Holy Symbol: Ice, Snow, White Feathers
Portfolio: Winter

4E PHB Equivalent: Formerly The Raven Queen

5E Domains: Nature, Tempest

Once known as the Raven Queen, goddess of Death, Fate and Winter, much of her power was stolen by the hero Waylander, who became the new God of Death. Now the Winter Queen is one of his greatest rivals, and seeks revenge.

The Tree of Life

Alignment: Unaligned
Holy Symbol: White Tree
Portfolio: Fey creatures, Art, Magic, the Feywild

PHB Equivalent: Corellon

5E Domains: Life, Nature

Situated at the center fo the Realm of Thanadiel, the Tree of Life is a gargantuan tree with a silver bark and platinum leaves. It communicates empathically with Eladrin and Elves who worship it, and seem to have power over the Land itself.

Supreme Church of the Light

Alignment: Good
Holy Symbol: Golden Sun on White
Portfolio: Peace, Friendship, Light

4E PHB Equivalent: Pelor

5E Domains: Life, Light

A rising religion among the desperate people of Tyrrah, the Light promises salvation, redemption and peace, and all it asks in return is Devotion. A very popular religion among commoners, and those who cannot defend themselves against the encroaching Darkness.

Imperial Church of Athun

Alignment: Unaligned
Holy Symbol: Golden Hammer on Red
Portfolio: Victory, Human Culture, Honor

4E PHB Equivalent: Kord

5E Domains: Tempest, War

Thunder echoes across the countryside. Threatening dark clouds tumble down from the frozen north. Rain lashes the shores, while reavers on dragon-prow ships scour the seas, searching for glory, battle, and plunder. Smoke and death drifts on the wind, carrying with them the sounds of clashing steel and death cries from the fallen. And in all these things is Athun— he who is named Storm Father, Lord of Battle, and Warmaster.

Athun is no god for the faint of heart. Weakness has no place in the Storm Father’s eyes. Athun demands prowess, courage, and strength in his followers, but he offers much in return—with power and glory at the forefront. For all his ferocity, Athun is not wanton in his destruction—such slaughter is best left to lesser gods. Wisdom tempers his wrath, and he is quick to offer mercy to those who admit they are less than he. In this way, Athun is an honorable warrior, but he is also no fool. Those who cross him find swift and final death because Athun brooks no betrayal and punishes all who wrong him and his own.

To be accepted into Athun’s service requires much from the petitioner. A devotee must demonstrate strength, courage, and ferocity—qualities Athun respects. Moreover, candidates must display devotion to excellence in all they do. Often, priests undergo punishing rites and trials to test their endurance. They might quest against the Warmaster’s enemies, withstand brutal beatings by elder priests, and spend countless hours training with myriad weapons. Those who fail are never scorned, but they are praised for their willingness to try. Those who succeed are welcomed with great celebration into the Battle Lord’s retinue.

The Circle

Alignment: Unaligned
Holy Symbol: Green Circle on Brown
Portfolio: the World of Tyrrah, Nature, Balance

4E PHB Equivalent: Melora

5E Domains: Nature or Druid class

The Circle is an organization of Druids, Shamans, and others who believe that the World of Tyrrah itself is a Divine entity to be venerated and served. They strive to maintain the Balance, and to bring Tyrrah eco-system back to normal.

Cult of the Black Moon

Alignment: Evil
Holy Symbol: Black Moon on Purple
Portfolio: Domination, Darkness, Undeath, Murder

5E Domains: Death, Trickery, War

The Cult of the Black Moon is an ancient force that has plagued Tyrrah since the Dawn of Time. The Cult is banned in most lands, and only in Xogotha, the Devilish City of the North, the priests of this infamous cult are allowed to walk freely, and thrive.

The Black Moon seeks to enslave all the lands of Tyrrah, and will use any means, Devilish, Demonic, Undead, or monstrous to achieve its plans.

Some cults do not venerate the Black Moon as a whole, but prefer to focus on one particular aspect, represented by on of the Six Unholy Archons of the Black Moon:

Asmodeus is the evil Unholy Archon of the Nine Hells. He is patron of the powerful, archon of tyranny and domination, and the commander of devils.

Bane is the evil Unholy Archon of war and conquest. Militaristic nations of humans and goblins serve him and conquer in his name.

Gruumsh is the chaotic evil Unholy Archon of destruction, lord of marauding barbarian hordes. Where Bane commands conquest, Gruumsh exhorts his followers to slaughter and pillage. Orcs are his most fervent followers.

Torog is the evil Unholy Archon of the Underdark, patron of jailers and torturers. Common superstition holds that if his name is spoken, the King that Crawls will burrow up from below and drag the hapless speaker underground to an eternity of imprisonment and torture.

Vecna is the evil Unholy Archon of undead, necromancy, and secrets. He rules that which is not meant to be known and that which people wish to keep secret.

Zehir is the evil Unholy Archon of darkness, poison, and assassins. Snakes are his favored creation, and the yuan-ti revere him above all other gods.

Children of Bahamut

Alignment: Lawful Good
Holy Symbol: Platinum Dragon on Sky Blue
Portfolio: Good Dragons, Dragonborn culture, Royalty

4E PHB Equivalent: Bahamut

5E Domains: Life, War

Called the Platinum Dragon, Bahamut is the god of justice, protection, nobility, and honor. Lawful good paladins often revere him, and metallic
dragons worship him as the first of their kind. Monarchs are crowned in his name. He commands his followers thus:
✦ Uphold the highest ideals of honor and justice.
✦ Be constantly vigilant against evil and oppose it on all fronts.
✦ Protect the weak, liberate the oppressed, and defend just order.

Spawn of Tiamat

Aligment: Evil
Holy Symbol: 5-headed Dragon on Night Blue
Portfolio: Greed, Evil Dragons

5E Domains: Death, Trickery

Tiamat is the evil god of wealth, greed, and envy. She urges her followers to take vengeance for every slight, and she is the patron of chromatic dragons.

Primordials

Alignment: Chaotic Evil
Holy Symbol: The Pure Elements, Storms
Portofolio: Chaos, Destruction, the Elements

5E Domains: Nature (earth), Light (fire), Life (water), Tempest (air)

Many barbaric tribes of humanoids revere the destructive energies of the elements as living Gods, pledging their allegiance to Primordial Lords in exchange for rage and fury in battle.

The Wanderer

Alignment: Good
Holy Symbol: Stone Disk on Animal Hide
Portfolio: Freedom, Adventure, Luck

4E PHB Equivalent: Avandra

5E Domains: Knowledge, Trickery

The Wanderer is an aloof God who demands nothing from his followers, only that they live a free and full life. There are no big cathedrals dedicated to him, only small shrines on the side of travelled roads.

Enlightened Way of Perfection

Alignment: Unaligned
Holy Symbol: Three Golden Circles, crossing, on Green
Portfolio: Perfection, Order, Discipline, Menthat Culture

4E PHB Equivalent: Erathis

5E Domains: None, Monks (and Psions)

A phylosophy more that a religion, the Enlightened Way is embraced by Monks and Psions, and those who choose to live a meditative life. Many followers and "priests" of this philosophy are in fact psychic able individuals.

Cult of the Spider Queen

Alignment: Chaotic Evil
Holy Symbol: Purple Spider on Black, A Spider with a Female Drow face.
Portfolio: Dark Elves Culture, Murder, Fate

5E Domains: Trickery

The Spider Queen is the chaotic evil goddess of shadow, lies, and spiders. Scheming and treachery are her commands, and her clerics are a constant force of disruption in the otherwise stable society of the evil drow. After the events that led to the death of Orcus, and the ascension of Waylander, she aquired the portfolio of Fate.

The Great Dwarven Fathers

Alignment: Lawful Good
Holy Symbol: A Mithril Gate
Portfolio: Dwarven Culture, Mountains, Forge, Creation

4E PHB Equivalent: Moradin

5E Domains: Knowledge, War

Dwarves revere and worship their ancestors, and each Clan or Family has its own Patron or Matron. Their sacred duty is to guard the Gates at the End of the World, a task that Dwarven Clerics and Paladin take great pride in performing.