Below is an article that discusses ways to use arcs and growth to deepen your characters.
I agree with the points that Jason Black offers, but I would add that character arcs do not have to lead to an ending where the character “becomes a better person.” Tragedy can be just as compelling. Some of the best character arcs/story arcs are what I would term “hero’s fall” arcs.
It is quite commonplace to start with a mundane protagonist and, through your story, build them into a hero. This would be a “hero’s rise” sort of arc, and they are probably the most common in fantasy. However, starting with a powerful hero and having them lose in the end can be very powerful. Just look at the appeal of Anakin Skywalker. Or Shakespeare’s most famous works. People can related to failure, perhaps more than they can relate to heroics.
But if you’re writing a rising character arc, it would be helpful to read over Black’s tips.
Seven Ways to Show Character Growth
(by Jason Black)
The best novels offer a strong storyline coupled with a strong character arc. A character arc is nothing more than the inner process by which a character becomes a better person. When the events in a storyline, coupled with how a character reacts to them, cause the character to become in some way a more mature person, that’s a character arc… READ MORE