In most stories, the hero is the most common person you can imagine, but then some mentor tells him or her that he or she is special. Or in some other cases, an accident, incident or experiment changes them into a stronger being.
The answer to the question you presented above would be 'persuasive speech' or 'oral persuasion'. These are the terms that refer to a speaker's use of persuasive language to persuade an audience.
An avocado is green and has a hard "skin". The skin is bumpy and you can use avocados to make guacamole. Kiwi has a soft skin and is very fuzzy.