What is Godwyn turning into?
If players delve deep enough into the lands below the Lands Between, they'll find Godwyn's "corpse" intertwined with the roots of the Erdree, a tumor injecting poison into the earth. Godwyn is no longer his handsome self, either, instead transformed into a monstrous shape.
Thus, Fia's purpose to join Godwyn is to reintroduce mortality to the Lands Between. Though such a fate may sound macabre, it actually frees Those Who Live In Death who have been waiting to pass while also allowing Destined Death to reach the demigods who have become mad with age.
Elden Ring: Age of Duskborn is One of Its Good Endings
Ending persecution of the undead, or Those Who Live in Death, may be an off-putting goal, but it still proves to be a good ending.
Julianna Swickard of CBR also debated whether Ranni was good or evil, arriving at the conclusion that while she was morally grey as a character, her ending was the "best possible outcome" of all the game's endings.
The reason Ranni had Godwyn killed was for a ritual. She wanted to destroy her body but preserve her soul in a doll. This way, she could escape her destiny and not be bound by the whims of the Greater Will like the rest of her family. It was this act that really made the plot of Elden Ring begin.
Lunar Princess Ranni assassinated Godwyn with the help of her Black Knife Assassins, causing Queen Marika to shatter the Elden Ring in her distress. However, striking down a Demigod isn't easy, which is why Ranni imbued the Assassins' Daggers with the Rune of Death, stolen from Maliketh.
The exact details of the night are not revealed to us, but the assassins managed to restrain Godwyn and killed him with their special Black Knives. This act killed the soul of Godwyn, but not his flesh.
Godwyn the Golden lead the charge in the dragon war and defeated the ancient dragon called Fortissax. After the defeat, the two actually befriended each other and that lead to the capital housing an ancient dragon cult.
Radagon is her second spouse and Elden Lord, a red-headed champion who mastered magic and incantations. All of this is well known and communicated to players early on, but what is less well known is the fact that Radagon and Marika are one and the same.
You'll receive the Frenzied Flame Seal, which strengthens Frenzied Flame Incantations. There seems to be no effect on the Lord of Frenzied Flame ending whether you complete Hyetta's quest or not, though.
Why does Melina sacrifice herself?
She also shows that she's not afraid of death as she willingly sacrifices herself to allow the player to advance and become Elden Lord.
In the Age of the Stars ending, Ranni refers to the Tarnished as her "lord" and her "dear consort", showing that she has not just acknowledged them as being Elden Lord, but also fully acknowledged their own spouse by her side.

Radagon is a major antagonist of the 2022 video game, Elden Ring. He is the male half of Marika and the protector of the Elden Ring.
The Fingers and Ranni are in direct opposition, but neither one is “good” or “evil”; the former seeks to maintain the status quo (quite like keeping the Flame alight in Dark Souls' ending), while the latter wants something brand new for everyone who's suffering as a result of said status quo.
But the Two Fingers had placed a curse on Blaidd - if Ranni ever abandoned her destiny, Blaidd would lose himself, becoming bloodthirsty with an uncontrollable urge to kill. He would go feral. In defiance of the fate he was born to, Blaidd swore to serve no master but Ranni.
However, as you play the game and learn more about the state of the world, one central character emerges: Lunar Princess Ranni. She is Elden Ring's greatest hero and most vile villain. Nearly every bit of pain and suffering you witness is a direct consequence of her actions.
After obtaining the Death rune, Ranni uses it to separate herself from the Greater Will. This causes her physical body to die, yet her spirit is still intact. For some unknown reason, Ranni decides to possess the body of a doll. The body hinders her in some way as she is in a more weakened state.
The deathbed companion Fia would become a leading figure among Those Who Live in Death, eventually making her way to Godwyn's corpse. Having received the other half of the cursemark from Ranni's discarded body with help from a Tarnished champion, Fia lay with Godwyn to grant him a second life as the Prince of Death.
Not much is known about the history and origins of the Black Knife Assassins, except that they're all women and highly skilled warriors. As per the item description of the Black Knife Armor set, they belong to the Numen race that has its roots outside The Lands Between.
What is the reason the black knife gang went to assassinate Blaidd and Iji after Ranni is put to rest? The main theory is that they were sent by the Two Fingers to kill them for betraying the Greater Will. Ranni was a target as well as seen with the Baleful Shadow.
Is Godwyn Godricks brother?
Godrick the Golden, more commonly known as Godrick the Grafted, was a scion of the Golden Lineage, tracing his descent from Queen Marika the Eternal and the first Elden Lord, Godfrey, presumably through their eldest son, the demigod Godwyn the Golden.
7 Morgott/Margit Defeated Radahn
General Radahn is generally considered by most Elden Ring characters as the strongest demigod, except it seems even the strongest don't always win.
Since players never fight Miquella, it makes sense why his Great Rune is never used, but it seems as though there was once a version of the game in which Miquella had a greater presence. Elden Ring is available on PC, PS4, PS5, Xbox One, and Xbox Series X/S.
Melina, too, is searching for her own path, but she shows her opposition to the Greater Will in her willingness to be the kindling for burning the Erdtree, an act she calls a cardinal sin. Queen Marika, mother of demi-gods, is Melina's mother, making Melina a demi-god and, therefore, Ranni's sister.
The clue left outside the Statue of Radagon hints at this word - Regression - and simply casting the spell in front of the Statue reveals its secret. Unlike most Incantations, Law of Regression is based on Int rather than Faith as it is a Golden Order Incantation.
The Offspring Of Marika And Radagon
When Marika took Radagon as her consort and Elden Lord, they produced two children: the twins Malenia and Miquella, who also attained status as Empyreans.
Lunar Princess Ranni is the daughter of Radagon, a champion of the Golden Order, and Queen Rennala, head of both the Carian Royal Family and the Academy of Raya Lucaria. Ranni had two siblings, Radahn and Rykard.
Godrick the Golden, more commonly known as Godrick the Grafted, was a scion of the Golden Lineage, tracing his descent from Queen Marika the Eternal and the first Elden Lord, Godfrey, presumably through their eldest son, the demigod Godwyn the Golden.
All of this is well known and communicated to players early on, but what is less well known is the fact that Radagon and Marika are one and the same. When the player finds Marika at the end of the game, she transforms into Radagon, and later becomes Marika again.
After Godwyn's death and the exile of Godfrey, Radagon was led back to return to Marika and marry her, becoming the second Elden Lord.
Who is Radahn married to?
Radagon and Rennala would go on to have three children; Radahn, Rykard and Ranni. While a husband to Rennala, Radagon studied the glintstone sorcery taught in the academy. After Godfrey the First Elden Lord was stripped of grace and hounded from the Lands Between, Radagon was summoned to the side of Queen Marika.
Ranni the Witch, also known as Renna, is a supporting character in the 2022 video game, Elden Ring. She also serves as the deuteragonist of her own quest line. She is a four-armed witch that happens to be the demigod daughter of Radagon and Rennala, making her the sister of Radahn and Rykard.
There are hints in the game suggesting that Melina is another child of Radagon and Marika: The Naming Convention; most siblings in the lands between share the first letter of their name, Melina/Malenia/Miquella would be no exception to this rule.
The Offspring Of Marika And Radagon
When Marika took Radagon as her consort and Elden Lord, they produced two children: the twins Malenia and Miquella, who also attained status as Empyreans. The former received her father's red hair, while the latter seems to have inherited the golden blonde hair of his mother.
The Children Of Rennala And Radagon
Rennala is royalty (not a god), but since Radagon is a god, they had three demigod children: Radahn, Ranni, and Rykard.
She was an Empyrean who ascended to godhood and became ruler of the Lands Between.Marika had a male self by the name of Radagon. As an Empyrean, she was gifted a Shadow, her half-brother Maliketh. Achieving godhood as the vessel of the Elden Ring, Marika took a consort, Godfrey, who thus became the first Elden Lord.