The Hero title is preferentially awarded to individuals with high levels in the Hero skill, although ruler authority can be used to reject the title. Additionally, the Hero title is given to the human that best suits the role based on overall strength and personality, with the latter seeming taking a priority.
Year 856: Shun becomes Hero when Julius is killed by Shiro
In the Yen Press translation of Volume 7, the Hero skill and title is incorrectly described as having granted Kumoko the skill Miracle Magic LV10. Miracle Magic is granted as a property of the Ruler of Charity title.