Villains who are biological relatives of heroes or any major protagonists, such as being parents, siblings, grandparents, ancestors, cousins, children, grandchildren, uncles/aunts, nieces/nephews, descendants, distant relatives, or even clones of heroes.

This is a common trend in fiction in an attempt to add drama and to a lesser extent, irony to the story. Indeed, having to fight a close relative is a source of much inner turmoil to the hero who cannot reconcile their quest and familial ties. Often, this results in the villain attempting to turn the hero over to their side, though this can fail, especially when the hero meets the criteria of Pure Good. Other times, the opposite will occur and the hero will attempt to turn the villain back to their side, which can eventually lead to redemption. (The perfect example, of course, is Darth Vader). However, some hero-related villains can be Pure Evil if they have no affection and feeling of love towards the heroes while meeting all the criteria (e.g. Scar, Trigon, Ego, Odalia Blight, Shao Kahn, Aku, Henry Evans, High Priestess, Ozai, Rip Blazkowicz, Emperor Belos, Unalaq, and Light Yagami).