Vendetta: A blood feud. An often prolonged series of retaliatory, vengeful, or hostile acts or exchange of such acts.
Characters that have a serious bone to pick with someone, or many people for that matter can be particularly enjoyable. Seeing their journey from disadvantaged character to rogueish outlier turned killer can be very rewarding.
Agent, Assassin, Mercenary: This type of character is often represented as the one who goes nuts and kills everyone. Vengeance takes many forms and some are more violently expressed than others. The paid-for-hire killer or spy, who might be excellent in their trade, but they eventually are done in by their own agency or organization. If they have the opportunity to carry out their revenge, their efforts are costly and their actions are usually even more heinous than the horrific crimes that had been committed against them. The blowback of their actions is not wholly unjustified, and they are often vindicated by whatever manner of retributive justice they pursue. Characters from films like Kill Bill, John Wyck, Jason Bourne, and V for Vendetta come to mind. For some characters, when everything has been taken from them, and they have no former life to return to, the only choice for them is revenge, and the only course of action they can immediately pursue is vengeance. It seems they can only find closure or a kind of salvation by taking this path.
Revival: A resurrection or reawakening of a character may give rise to the most unforgiving aggression of said figure. Now they have been brought back to life, resuscitated, and unleashed they have unresolved business to attend to. They may immediately seek out their enemies or all of their surviving kin, they might obliterate everything in their path and become a scourge upon the earth. The character and what form of host, life-form, and stability they possess once they are resurrected, can also matter. If they experienced a particularly gruesome death, and they are hell-bent on destruction, their revival might mean chaos and only that. The chain of events from revival to revenge can sometimes be less about the replication of scenarios and repeated events, and more about identifying the causal reaction. What in fact would be the likeliest recourse taken by the character? How would they respond? Sometimes repetition of certain actions is less about determining predictability, and more about identifying the likeliest outcome to transpire. This can be why characters who may appear to duplicate or copy others when in fact they are demonstrating already identified patterns in behavior. A killer whose murders replicate the similar manner in which they were killed. If they died among their own family, clan, entourage or group of some kind, and they all come back from the dead and repeat the similar circumstances of their deaths onto others.
Supernatural Vendettas: When a specific character or host of them do not pass over into the afterlife and an evil residuum exists. Evil spirits, witches, and ghosts in horror films often follow this kind of plot. They likely have been wronged in their previous lives and what is left behind is a brooding malignant spirit that still lingers. Films like The Grudge come to mind. These types of movies focus on a family, couple, or specific individual that moves into a haunted or cursed home or property where such a ghost is believed to still reside. Until restitution is paid in some form, or an acknowledgment of past crimes committed is shed light upon, the hauntings, murders, and other supernatural activity will still continue.
An Eye for an Eye: When the vendetta is pursued in the form of a human counterpart or human currency that must be exchanged where one character who has lost someone they love, expressly prioritizes taking the life of their enemy or someone whom they love as retribution. A certain character from the film The Princess Bride made it his life's mission to avenge his father who was taken from him as a child and killed. There is also the famous quote from a certain religious figure that suggests the blinding of the world which occurs by everyone plucking out each others eyes, and there is much truth to this, yet the world is still populated by petty and vengeful individuals and most people still have their sight intact.
Hostages: When other characters or victims are kidnapped and held for ransom or some form of corollary in exchange for their safe return. This type of human collateral often is very remorseless as the person or number of people taken may have considerable meaning, weight, and sentimental value to other characters. The act of taking hostages is not simply an emotional wounding through taking someone that another person cares for deeply, but it is also a power play as it demonstrates the act of tactful infiltration, and communicates to another character that they are never safe, and that dangerous people can get to them whenever they decide to. This differs from the previous example in that there is a timeline of waiting involved in hostage situations, where every minute of the crisis is taxing, and characters are left wondering if those taken will ever survive. Psychologically it is meant to be torturous and it is drawn out differently and more painstakingly than a quick execution, murder, or hit-and-run. When the hostage is maimed or injured in such a way that sends a message to the other side, this can hasten the negotiation process and raise the stakes. If the hostage is inches away from death, and the situation is dire, they may be one step closer to concluding the exchange. Whether or not it is the preferred outcome or resolution depends on the circumstances.
Lovers Quarrels: Feuding partners. Love Triangles. Resentful or Jealous Spouses. Messy splits or divorces. The battleground of relationships is filled with many opportunities to get back at or get even with former loved ones. In many instances, these actions can result only in wasted time, money, and resources yet some characters cannot seem to let the feud be laid to rest. For a lot of characters and couples, it never seems to dawn on some of them that they can hate those they formerly loved, with the same amount of zeal and emotion that caused them to be as interested in them as they were in the first place. And many characters never seem to think they can be brought to such a vitriolic place of hatred towards a former partner. But when that emotional switch has been flipped, the vengeful actions taken against them prove that the love was never as sound as they led themselves to believe. It is also very telling to see just how characters respond when things don't go their way in a relationship. As if acting like the vengeful and jealous partner is going to improve matters, or get them back, yet some characters go to absurd lengths just to prove a point. For some characters, the vendetta can be about a claim over a former loved one, which can result in many ruinous actions that are taken in order to declare ownership over another specific character. Royal blood-lines of Queens, Princes and Princesses, brides and sovereigns to be, and their prospective suitors can often follow this plot.