Morgoth. It is a name from Tolkien's legendarium, representing a great and evil power.
Lilith. In many mythologies, Lilith is seen as a dark and somewhat malevolent figure, so it would be a great evil name for a story.
Well, there's Mordred. In Arthurian legends, Mordred was a very devious character. Also, Cain is a name that brings to mind the first murderer in the Bible, so it can be considered an evil name for a story. And Vlad, as in Vlad the Impaler, who was known for his extreme cruelty.
You could consider names like 'The Dark Lord', 'Malice Master', or 'Sinister Soul'.
Some possible evil names for stories could be 'The Cursed Covenant', which gives a sense of something being wrong with an agreement. Another one is 'The Malevolent Mirage', suggesting a false and evil appearance. 'The Wicked Whisper' also works well as it implies an evil voice or influence.
Raven. Ravens are often associated with death and darkness in many cultures. Using it as a name can bring an air of mystery and evil to a story. For example, a character named Raven could be a brooding villain who lurks in the shadows.
For good names, 'Elysium' is not very common but it refers to a place of great beauty and peace in Greek mythology, so it could be a great name for a good entity in a story. 'Avalon' is also an uncommon one, often associated with a magical and idyllic place. For evil names, 'Abaddon' is an unusual but very effective name. It is often associated with the underworld or a place of destruction in religious texts. 'Mordred' is another less - common name that has evil connotations from Arthurian legend.
Some possible names could be 'The Dark Covenant', 'The Shadow Syndicate' or 'The Malevolent Order'.
Lilith. In many stories, Lilith is often depicted as a rather evil or at least very independent and somewhat menacing female figure. She has her own origin stories in various mythologies and is associated with darkness and disobedience.
Some evil shark names for stories could be 'Razorfin'. The word 'razor' gives the impression of something sharp and dangerous, just like a shark's fin can be a menacing sight. Another name could be 'Bloodjaw'. It implies that this shark is associated with bloodshed and has a powerful, perhaps menacing jaw. Also, 'Shadowstalker' is a good name. Sharks are often stealthy hunters, like a stalker in the shadows, ready to pounce on its prey.
Lilith. In some stories, Lilith is often depicted as a very independent and somewhat malevolent figure. Another one could be Morgana. Morgana from Arthurian legends is known for her dark magic and schemes. And then there's Belladonna, which is also associated with poison and danger in many fictional concepts.