Bloodstained: Curse of the Moon/Endings

Endings
In normal mode, there are 5 different endings based on how you interacted with the other characters. At the end of each of the first three stages, you encounter another character. You can either team up with them, kill them, or just keep walking and ignore them entirely.

To get the true ending of the game, you must get the "Those Left Behind" ending, which will unlock Nightmare mode. Complete Nightmare mode to see the true end, "Fallen Moon’s Requiem."

Those Left Behind (True Ending)
To get this ending, complete normal mode while allying with all three characters. This will unlock nightmare mode.

Zangetsu saves his allies from Gremory's final attack. He succumbs to the darkness, and his allies set off to try and save him.

Fallen Moon's Requiem (True Nightmare Mode Ending)
To get this ending, complete nightmare mode.

Zangetsu's allies defeat him, and while they fail to save his life, his soul moves on to the afterlife. After the credits, Zangetsu wakes up in the city from Azure Striker Gunvolt.

Nightmare's End (Good Ending)
To get this ending, ignore every ally.

Zangetsu defeats Gremory, but is powerless to stop her final attack. At the last moment, Miriam, Alfred, and Gebel jump in and sacrifice themselves to save him. Zangetsu escapes and watches the castle crumble. Peace returns to the land, and, moved by their sacrifice, Zangetsu feels a change in his heart.

Blade Gleaming at Sunrise (Normal Ending)
To get this ending, ally with one OR two of the other characters, and ignore the rest (do not kill them).

Gremory is defeated, and Zangetsu and his ally/allies watch the castle crumble. Peace returns to the land, and the allies go their separate ways, but Zangetsu's heart is still plagued by darkness.

That Man, Zangetsu (Normal Ending 2)
To get this ending, kill one or two allies and ignore the rest. Do not ally with any.

Gremory is defeated, and Zangetsu watches the castle crumble. Peace returns to the land, but Zangetsu's heart is still plagued by darkness.

Emperor of the Dark (Bad Ending)
To get this ending, kill all three other characters when you meet them as Zangetsu.

Zangetsu defeats Gremory and takes her power, becoming the new dark emperor.