A wronged group, maybe a clan like the Uchiha or a ethnicy like Ishvalans, can include fantasy prejudice. The 'last survivor' can be used as a pawn to get something that only his/her people can (money, a bloodline, mcguffin, knowledge).

Sealing/Killing someone because they are too dangerous/power to be free, bonus if they try to use them as an weapon, power source or a battery of sorts. To power an city? Suply magic? Use their powers for something (I am still pissed at Hashirama for the Jinchuuriki bullshit, fuck him).

An friend being mindcontroled/possessed/infected, turned into an monster, having an cursed power or whatever and the 'good guys' want to simple kill them. Or nuke an city for similar reasons.

Capitalism. This one has a lot of opportunities to work with. Or anything similar to real life with an fantasy version, like an race having blood that can heal or cry jewels (like koorimes in YYH), fur or bones wanted in the market, or creature (sapient?) being keep an prized pet, an magical type of tree that is needed to make something. A bad product/drug (can be an 'good' product, like one that heals, but made of people resources), ingredients for potions or delicacy, entrainment (what type? songs? carriage?) . Maybe a nobleman wanting (or feeling entitled to it, duo begin descendants of a Hero or something like that?) to have a magical creature or artefact (Mononoke has something similar).

Tropes Names: Solid Gold Poop, Fantastic Medicinal Bodily Product, Eye of Newt, Sapient Fur Trade, Supernatural Human Trafficking, Human Resources, Industrialized Evil, People Farm.

Light vs Dark with a Twist. A certain type of things are 'forbidden' or 'dark' without much of a good explanation. Or unnatural. Bonus if religion intolerance is included. I know people that think the weirdest things are of the devil.

Something similar to HP's wizard community with magical creatures in general and muggles. Fuck them. If is a crossover with a character belonging to a magical species (like in Trollhunters) you can bet they will try to use their 'laws' (created by wizards without consulting the people they are made for) to control the character.

Messing with people's soul, body or powers or something like that, 'breaking', sealing or changing it to suit your plans and benefit you.

Using people as a sacrifice of sorts for the 'Greater Good'. Anything to do with the 'Greater Good'. Or 'for the progress', 'for the science', 'for the motherfucking pRoFiT'...

'Superheroes' that think their position as the 'protectors' give them the right to do whatever they want (like stalk and harass people and take their DNA without consent for test just because they are 'suspicious'). Stealing objects for 'curiosity' and make tests or weapons with them are pretty common routes too in that type of story.

You cannot break in people's houses, search/examine their things and demand them to come with you, 'you have questions' my ass. They have rights and if you don't have a warrant, you need to get the hell out of my house.

Meddling and fucking up everything.

When a group is trying to defeat a villain or in a quest and another one far to 'curious' try to find information about them and end up fucking up a lot. This one is more crossover like. Avengers, Soul Society, Wizard World are some of the assholes in question, often occurs an kidnapping, ilegal imprisonment and attempt 'interrogation' to see if they are an 'threat' (nevermind who is kidnapping who here buddy), I get pissed when they are forgiven easily or if they just spill information like idiots.

Cultural Appropriation, Modification and Erasure. Fetishzation, acting condescending (even if you have good intentions), denial and attempt hidding of the advancement or great achievement of the prejudiced folk, segregation, stereotype. It can be clothes, techniques, festivals, languages, books, folklore, architeture, traditions, mythology, symbols, monuments, cities, songs, image, words, names (of places and people)...

Other types of appropriation too, like the rich elite/politians invade and take over a movement/form of art/ideology for themselves. Or like the swastikas, used by a evil ideology.

Make the Leader/Ruler join so the other will too. Take over/Absorve another faction within yours. Create a system that centralizes power and control.

Make someone and their friends/family an target of your enemy to force them to join/help you. Kind of 'our enemies think you are one of ours, they will attack you.'

Any type of attempt to make another people to fight for you in your wars, probally by forcing them to join an 'secret world' by drawing the villains's attention to them or revealing your location to them, making them believe 'oh, they will go after you anyway, its better if you join us', plenty of manipulation involved (to get the into trouble, to fight, to steal, stop them from leaving an place where you have more power). Can manipule the villains to kidnap or experiment on them, so you don't need to do it yourself.

Use of of your own as hostage/bait when your subordinade/child befriends an powerful person (or dunno, a defector? Someone you want to recruit?). This person in question (often an minor) is under your custody. Or to get/find something because of their relations (blood or not) with another faction/group family.

An Fight is an Trap (forced recruitment maybe, like...in an 'official' duel/tourment would announce they belong to an certain group). The Ring Battle in pretty much a trap for Xanxus to swear loyality to Vongola.

Mindfucked and forced into another identity.

I read an few interesting stories where an woman is seduced/mind controled to marry an man, because of her (unknow for her) bloodline/power. More often than not, she's the MC's mother. Ex: Kushina, Lily and Nana.

Unknown Siblings are also very common. Either killed/rebeled/hidden/used by the manipulator, given away or bastard children being taken from their mothers. Maybe one parent lied to their partner about their baby being stillborn and kidnapped him/her to another place or your parent(s) is not your real parent(s). Maybe your Bad Father had a bastard child he hides. I read a good reincarnation crossover about Naruto's older sister being MIA during the Kyuubi attack because Sarutobi wanted Naruto be raised as a no-named orphan, so she was trained and hidden by Danzo. KHR often has Tsuna having a brother Iemitsu took (kidnapped) to Italy, or just dragging the Vongola heir (his kid or not) to the Iron Fort without nobody consent.

An magical society is slowy losing their powers due incest and the nobles choose to go through drastic ways to get their power back. Can lead to warm to pure magical criatures like fairies. Maybe thats how the first magicals got their powers?

I kike the concept of a evil person or group losing any type of power and their attempt to get it back.

The monopoly of magic (or similar). A commoner (or a character who is considered 'lesser' in some way) having a power/doing something only a noble family could have (or wants everyone to believe is a noble blood's power and belongs only to them). If its a 'Magic is coning back' even better, please don't make the commoner be a long lost noble heir.

Wanting to kill an person because he/she is an 'mistake' of sorts, either they are an threat for an 'balance', survived an purge or source/key. Or an dangerous power or nature or 'bad luck' (leave black cats and albinos in peace) in some way. It also can your own worldbuilding 'version' of Witch Trials.

Attempt to force a powerful person to marry, either because you want their throne/propriety (usurpation by marriage), children with an certain bloodline power, powerful heirs (when you want to marry them to you or your own children), the loyality of said person or to force them to join your faction by association with their 'spouse'.

The said spouse can be weak (so they won't have their support), a loyal spy, a black widow...they will probally get rid of you after a kid or two are born.

Or maybe its your parents that wants to use you to do this to another person.

On another character's perspective, if the bloodline/power/heritage/whatever comes from the good parent, the evil one is going to manipulate the hell out of the kid. If the kid raised away from them (hidden?), even better. Or maybe the kid becomes the other parents's enemy (which parent? The evil or the good one?)

Did I mention how much I like bloodline plots? Todoroki Rei and Ursa from Avatar both fit this. Clara from the Other Side of Paradise kinda too. Thrax, the cruel son of Hippolyta and Ares that was killed by his own mother

One fantasy species wants/needs to use another for some reason (Resources? Source of power/energy? Food? Servants or Working Class? Labor? Reproduction? Parasyte? Army? Eggs? A Substance they naturally produce?), they could also have nature powers that serve to make the land fertil or maybe healing powers. If they had been using them for an long time, the entire society may turn dependant of it. More of an Grey situation.

Colonization, theft of resources, attempt to take over of local realms/tribes/kingdoms. Attempt to use someone army for your own benefit.

Pretty common in the Naruto/HP fandom, a character got adopted and the toxic birth family refuses to accept it, ignoring the existence of the foster family, calling him/her by birth name telling them its their 'real name', trying to bring you 'home' where they 'belong', dragging/shoving you back to their house or just try to stop you from leaving said house. Speaking of 'family' and 'filial duty' more often than not they want something of this so-called reconciliation, maybe they feel guilty of being bad parents and selfishly want their 'child' back or you are useful for them/they need you in some way. Attempt at toxic and clingly parenting after knowing you for less then week. They want you to abandon your loving foster family to stay with them forever and ignore the fact you explicit told them you want nothing to do with them. Can have they trying to take you from the school or hijacking your life and traps for forced surprise reunions, demands to have a part in your children's lives (and names too). Insistence that 'they are family' and you 'cannot leave them', 'I am your father, I have authority over you' demanding your time. Toxic attempts on bonding and 'getting to know you'. Maybe even a non-consensual blood test involved or stealing documents from the hospital. We need more KHR fic like this, Nana and Iemitsu are abusive as hell and delusional too.

Or just attempt to drag you back to your abusive family And if your birth parents are dead, bad distant relatives still can try to take you by force for some reason.

That works with former friends that fucked up and won't leave you in peace because they want you back.

Or absent parent thinking he has a right to your life. Imposed and forced relationships is the goddanmit summary of KHR, so is fucking up and all but demanding forgiveness. Or just a person that don't understand you don't want anything to do with them, leave me the fuck alone.

Or just begin estranged from your family and they want something from you (or your S/O and kids) years later

I am trying to list 'bashing ideas. Having a bit of trouble here, but until now I am going well. Its less bashing and more 'evil' actually. This word has an bad reputation.