One way is to look at the setting of your story. If it takes place in an old, abandoned mansion, you could have a title like 'The Dark Mansion's Secrets'. Another approach is to focus on the emotions in the story. If there is a lot of guilt, 'Guilt's Grip in the Dark' could be a unique title. You can also play with words that have double meanings related to darkness, like 'The Veil of Night' which not only refers to the night but also gives a sense of something hidden.
Think about dark places or events. For example, if your story involves a cemetery, you could name it 'The Secrets of the Cemetery'. Also, consider using words that have a negative connotation, such as 'forsaken', 'cursed', or 'abandoned'. So, a title like 'The Forsaken Village' would work well. You can also play with words that suggest a lack of hope, like 'Endless Gloom' or 'Hopeless Darkness'.
You can use strong adjectives. For example, 'The Ferocious Monster' or 'The Sinister Monster'.
You can use words related to family values like 'love', 'unity', 'heritage'. For example, 'Love in the Family Circle' or 'The Unity of Our Family'.
You can use words related to fear, like 'haunt', 'curse', 'evil'. For example, 'The Haunted Manor'. Also, think about settings that are spooky, such as 'The Graveyard at Dusk'.
You can focus on key elements of love. For example, use words related to the heart, like 'Heartbeats of Love'. Or think about the place where the love story happens, such as 'Love on the Seaside'.
Use strong, action - oriented verbs. For example, 'Conquering the Market: A Success Story'. The verb 'conquering' gives a sense of achievement and power.
You can focus on key elements like the destination in time, such as '1920s Time Travel'. Or use words that create a sense of mystery like 'The Enigma of Time Travel'.
You can use elements from the setting like 'The Ghost in the Foggy Marsh'. Or focus on a character trait, for example 'The Sinister Ghost'.
To create unique characters for an MLP Dark Mirror Universe fanfic, think about the values of the dark mirror world. If it's a world full of envy and hatred, then the characters should reflect that. You could combine different pony types in strange ways. Say, a half - unicorn, half - earth pony character with a split personality due to the chaos of the mirror universe. Also, consider their backstories. Maybe a character was once good in the normal universe but a tragic event in the mirror universe turned them evil. Give them names that sound menacing or different from the normal MLP names too.
One way is to focus on the main theme or mystery of the story. For example, if your story is about a girl finding a magic portal in her backyard, a title like 'The Magic Portal in the Backyard' directly refers to the main element. It gives readers an idea of what to expect.