In classic RPG fashion, Fear & Hunger has multiple endings. There are 9 in total — 5 normal (A-E) and 4 character-specific endings (S).
Normal Endings
Normal Endings (A-E) are common endings that can be achieved with any character. Endings A and C are not achievable in Hard mode, as the party members required to reach them cannot be recruited.
Ending A - "The God of Fear & Hunger"
To achieve this ending, the player has to keep the girl alive in their party, travel through the mouth of the God of the Depths by destroying their three hearts, and reach The Heart of Darkness, an area built out of corpses at the very bottom. A battle will initiate against the God of Fear and Hunger. Victory results in Ending A.
(Guide)
Ending B - "The Older one"
Similar to Ending A, the player needs to reach the pile of corpses through the mouth of the God of the Depths, this time without the girl in their party. Reaching the bottom will instead trigger a battle with Traces of Gro-goroth.
If the battle is won, Traces of Gro-goroth will ask the player why they continue to fight — whichever answer is given, Ending B is received.
Ending C - "The Yellow King"
For this ending, the player must find Le'garde alive and keep him in their party. It is required to reach the city of Ma'habre, get the tormented, endless, and enlightened souls, еnter the Golden Temple, and kill Francóis. After this, the player can sit on the Throne of Ascension — doing so teleports the party to The Void.
Once in the Void, after finding their party members (optional) and avoiding the Greater Blight, the player is suddenly forced to do battle with Traces of Sylvian (provided they are playing on Terror and Starvation difficulty).
After the battle, the player must reach the Yellow King, then reject his offer, and fight him. After winning you will get Ending C.
Ending C-II - "The prophecy"
Ending C-II is achieved with the same path as Ending C, but instead of fighting Le'garde, the player must kneel before him once in The Void. Doing so will let the player escape the dungeons of fear and hunger and receive Ending C-II.
Ending D - "A new god"
Same as the Ending C, the player needs to reach the city of Ma'habre, get the tormented, endless, and enlightened souls, kill Francóis, and sit on the Throne of Ascension. However, the player must not have Le'garde alive in their party.
After falling into The Void and battling Traces of Sylvian (provided they are playing on Terror and Starvation difficulty or Hard mode), the player will come to face a new, godly version of their character. It will ask a few questions. Regardless of what answer is chosen, you receive Ending D. To see all choices for this ending, see Ending D - Choice Dialogues.
Ending E - "Escape?"
To achieve this ending, the player must find Le'garde, dead or alive. After this event, it is possible to simply leave the dungeons through the starting gate. This triggers Ending E.
S Endings
S Endings are special, character-specific endings that can only be achieved in Hard mode and are not possible if the player becomes a Marriage or Marriage (Fusion) before the ending requirements are achieved.
To get the S Ending for Cahara, the player must find all three treasures from the maps of Isayah in Ma'habre, the last of which lets the mercenary obtain the King's crown. (Guide)
To achieve this rather difficult ending, the player must use Ragnvaldr and obtain every single specific soul in the game, meaning having to face almost every difficult encounter possible, needing several Empty scrolls, and having to solve the tomb statue puzzle. (Guide)
Canonical Ending
Warning: there is spoilers for Fear and Hunger 2: Termina!
From the lore of Termina, it appears that elements from several endings have been made canon, which makes it impossible to complete a canonically accurate run in Fear and Hunger. Due to that, we can only list elements that have been confirmed canon:
The Girl is taken into Level 9 of the dungeon, and ends up being transformed into the God of Fear & Hunger. It could only be speculated that Cahara was the one to bring her to the Level 9 section of the dungeon, as all the other playable characters have a potential, specific purpose they fulfill, whilst the Mercenary is not mentioned in Termina at all. This is supported by Miro Haverinen's Twitter account, where he states that Cahara's absence in Termina "tells a story too."
Le'garde achieves his goal and becomes a new god, thus surviving the first game's events. This gives D'arce a potential purpose to help Le'garde get to the Throne and become a new god, as using Rot on Le'garde in Termina transforms him into a similar creature as in D'arce's S Ending, but this is not confirmed, as Termina doesn't mention D'arce's fate.
Enki survives the first game's events as he is the Author of the Skin Bibles, which might potentially clash with the Le'garde bit of lore — if you attempt to choose Enki's S Ending as canon, the events that lead to the S ending clash with Le'garde's transformation into a new god. It's likely it was overlooked or simply doesn't matter in the actual lore, but it's food for thought on Enki's S ending canon status.
Ragnvaldr survives the first game's events, as it is implied that one of the participants in Termina's festival is his descendant. It is highly likely that Ragnvaldr's S Ending is canon, as aside to some potential enemies that could inhibit the validity of his S ending, generally he could slay all the creatures in the dungeon, making his S ending canon. It is not confirmed if Either Enki's S ending or Ragnvaldr's S ending are canon as stated above.
Moonless survives the first game's events and went on to travel with Ragnvaldr, as she appears in Termina as a potential boss encounter and a family friend of Ragnvaldr's descendant.
Nas'hrah survives the first game's events, as he appears in Termina as a "companion" of sorts that is recruitable. He's not counted like an official companion in Termina, though. He survived making contact with Gro-goroth which might state independently of any characters in Fear and Hunger.
Theories and Speculations
Warning: there is spoilers for Fear and Hunger 2: Termina!
While purely based on speculation, there are some theories that may or may not be canonical:
There is no confirmed theory that says the throne is only limited to one person, or has a potential "cooldown". It's possible for Enki to achieve his S Ending and then Le'garde, with or without the help of D'arce — neither is confirmed but one might be inclined to tie all major characters into the endings, picking that Le'garde became a new god with D'arce's help.
It's likely that all 4 playable characters entered the dungeon in similar periods of time. The first ending to occur would likely be Enki's S Ending, following that D'arce's S Ending (which then ties into Ending C partially), then Ragnavaldr's S Ending and finally Ending A. Enki has to open the gates to Ma'habre to allow all other endings to occur, following that the S Ending for D'arce and Ending C as it's never stated Ragnavaldr would have to possess all the souls and be the one to wipe out all the evil in the dungeon, but this is merely speculation to give room for D'arce and Le'garde to make their way into the throne room after Enki who would already have achieved enlightenment. Finally, all the creatures would have been slain, giving Cahara and the girl a fighting chance to make it through the Gauntlet.
