The same as when you help any other cat: the cat has been helped. If there is any effect beyond this, it will depend on the cat and how the cat feels about you. Cats of any color do not have extraordinary powers.
you get bad luck
Nothing happens, except now you have a dead cat. Don't "sacrifice" animals. It is both cruel and illegal.
its really creepy. but its not true
He begins abusing his wife and pet cat
No, however something like a cat who happens to be black IS considered unlucky by some people.
Cry to god for help.
No it is not. A black cat is a cat that happens to be black, nothing more. Because a cat's eyes have a reflective layer, a cat's eyes seem to make their own light at night. This has led foolish people to believe that cats are somehow supernatural, and black cats even more so, only because of their color.
he begins abusing his wife and pet cat
the kitty my go SPLAT! on your tires but hopefully, it never happens
Some of the figures of speech in "The Black Cat" by Edgar Allan Poe include personification (attributing human qualities to animals), symbolism (using elements to represent ideas), and irony (a contrast between what is expected and what actually happens). These literary devices help to enhance the eerie and suspenseful atmosphere of the story.
He starts abusing his wife and his favorite cat, Pluto --APEX
Maybe that just happens to be a color she likes. Some people like white or orange.