There are often self - made billionaires. These are characters who started from scratch and built their extreme wealth through hard work, innovation, or a bit of luck. Another type is the heir or heiress. They inherit their family's vast fortune and have to deal with the responsibilities and expectations that come with it.
In an 'extreme wealth system novel', you'll usually find the philanthropist. This character has extreme wealth but uses it to make a positive impact on society, whether it's through funding charities, building schools, or promoting environmental causes. Then there are the power - hungry antagonists. They are often jealous of the protagonist's newfound wealth or are trying to take over the wealth empire for their own gain. They create a lot of tension and conflict in the story.