These are just Urban Legends of the Game. While a lot of them have no factual evidence on them, some may be tied to some phenomenon that happened in game. If anything, just take the above stories with a bit of salt and just read them for entertainment. If you have your own Urban Legend to share, please do.
Story 1: The Ghost of Ciar Dungeon
It is said that in the early days of beta and g1 there used to be a ghost of a male and female model when you enter Ciar Dungeon. They sometimes appeared in the middle of rooms or sometimes out of the walls. Both the male and female would be together and constantly stay in the same spot.
It is said that when players walk away from them, they will secretly change their head's position to look at them but as soon as the player turn their camera angle back, they will look away.
It is also said that if one were to see them, an omen will befall them in that they will die at least once in the dungeon.
Story 2: The Ghost of Emain Macha
Rumors have it that if you were to stay sitting down infront of the altar of Emain Macha's church for an extended period of time, that a girl named Iris, dressed in a pure white idol ribbon dress would appear from the entrance. She will walk around the church crying for the church officials to release her husband and that her family is dying.
At first she appears to be a player character because she doesn't have the npc tag, but when one talks to her, she never responds.
When she is done yelling and begging, she will curse the Emain Macha Priest and cited that one day she will get revenge and she will walk outside the door of the church. If the player chooses to go out as soon as she does, she will not be outside the church at all.
Story 3: The Secret Steam and Dry Ovens of Shadow Taillteann
Legend has it that there is a steam oven at Shadow World Taillteann in that if you click on it, all successes will be 99% and you will be able to make all synthesis recipe regardless of your Synthesis Rank.
However to get to this oven, you need to be in a certain Shadow Mission and pick the right oven the first time. Should you pick the wrong oven first, you will no longer be able to pick the Secret Steam and Dry Ovens of Shadow Taillteann.
Which mission and which steam ovens/dry ovens are speculations.
Story 4: The Memory of Crumena
It is said that even after Crumena's death, that his memories will forever haunt the player as long as he or she is in Zardine. Every now and then, the Roar of Crumena can be heard against the player, desummoning his or her pet. It is Crumena's curse after his death in g8 and his curse will manifest themselves now and then.
Story 5: Excalibur
There is a story about a devCat programmer who implemented a quest in which the player can obtain Excalibur from the Lady of the Lake in Emain Macha. However, news was that the programmer decided to scrap the quest because the sword was too powerful.
However it is said that the programmer never truly removed the quest and that the quest can be unlocked by first solving the secret puzzle found on Emain Macha's lighthouse on the small island which will unlock the quest for Excalibur.
Story 6: The Legendary Knight's Appearence
Rumor has it that if a player was to win 1 million duels, the Legendary Knight would send a quest to fight the player personally himself. The duel would take place underneath Emain Macha in a secret Arena and at night time.
Should the player defeat the Legendary Knight, he/she will be awarded the "Faded Champion Armor" which grants 30% melee/range/mana pd, +200 defense, and +40% protection that has the ability to equip two accessories and the "Legendary Knight" title which grants +100 strength and +50% Critical Rate.
Who this Legendary Knight is never known, for when he is defeated, he simply vanishes, leaving only his armor and title.
Story 7: The Legendary Palace of the Sky
It is said that if you were able to collect all dungeon passes in Erinn, including Iria's statues, and Peaca passes, they will all combine into the Legendary Sky Pass in which the party leader and his party will be teleported to a dungeon above the skies where they will fight Valkyries and other airborne creatures.
The reward at the end is the Spear of Longitnus, the first true spear of the game.
Story 8: Mabi Mabi Milk
If a player plays "Epona's Song" perfectly infront of a cow, sometimes the cow will award "Mabi Mabi Milk" which, when drunk, will grant infinite mana and invulnerability for 3 whole minutes.
Story 9: Field Boss Prophecy
Sometimes when you sketch the normal variation of Giant Field Boss Monsters, you will end up with a sketch of the Giant Field Boss, and the location where it shows is where it will spawn next.
Hope you enjoy it!