race features:
Bloodfury: The scent of your blood in the heat of a battle enrages you. While you are below half your maximum hit points you may use your action make a special melee attack against one creature within your reach, striking with vicious ferocity. If your attack hits, you gain a number of temporary hit points equal to your Constitution modifier, and the target must make a Wisdom saving throw (DC equals 8 + your Proficiency bonus + your Constitution modifier) or be frightened of you until the end of its next turn. Once you use this trait, you can’t do so again until you finish a short or long rest.