But there nothing in there that stipulates anything about requiring a you warn an intruder. The statute above says that warning through brandishing is legal when necessary. In section 5, there is nothing about a warning having been issued to determine the reasonableness of the self defense claim. Am I missing something?

You may use lethal force to stop the commission of a forcible felony, no warning needed. Home intrusion is a forcible felony in progress, shoot first to stop the threat.