1) [A crank] considers himself a genius. (2) He regards his colleagues, without exception, as ignorant blockheads....(3) He believes himself unjustly persecuted and discriminated against. The recognized societies refuse to let him lecture. The journals reject his papers and either ignore his books or assign them to "enemies" for review. It is all part of a dastardly plot. It never occurs to the crank that this opposition may be due to error in his work....(4) He has strong compulsions to focus his attacks on the greatest scientists and the best-established theories. When Newton was the outstanding name in physics, eccentric works in that science were violently anti-Newton. Today, with Einstein the father-symbol of authority, a crank theory of physics is likely to attack Einstein....(5) He often has a tendency to write in a complex jargon, in many cases making use of terms and phrases he himself has coined.
Scientific cranks are a certain kind of crank, and crank-ery is a special kind of "deranged". A crank-y character might consider themselves to be superior to others. They might feel persecuted by the no-nothing establishment (mainstream science, mainstream media, mainstream anything). They may use a lot of made-up jargon. And they may compare themselves to people who have been historically understood as "great people".
The character described in the question likely sees themselves in opposition to others, thus it might help to try to get into the mindset of someone with whom you vociferously disagree, and try to write like they do. If you are an American Democrat and consider the far-right of the Republican party to be a bunch of fascists, pick your favorite bit of right-wing media, and emulate it's style. If you are an American Republican and consider the far-left of the Democratic party to be a bunch of commie-pinkos, do the same.
More broadly, you might seek out people who you, personally, believe are "deranged". The internet is full of fora for various groups of people who's world views are vastly different from the mainstream point of view. Reading the things written on those fora (or watching the YouTube videos they create, or however else you access their work) could be enlightening with respect to creating a "deranged" character. Collect up examples of such media, and emulate their style.
Again, the point is that people who are "deranged" usually have some internal consistency to their thinking. They might ignore evidence which contradicts their world view (indeed, contradictory evidence often solidifies one's prior assumptions), but their own, internal thinking will follow some kind of logic.
Finally, I would suggest empathy for the character. It is very easy to decide that a character is "deranged", and therefore have them say all manner of nonsense. This can easily make a character look like a strawman for an author to burn in effigy. Take the time to get some understanding of what the character actually believes about the world (whether true or not), and allow them to put forward the best arguments they can make. This will help to create a much more believable, three-dimensional character, even if they only ever get one paragraph of dialog.
"It's the Illuminati! They control everything! The, the TV, and the headlines! My god you don't know -- they've got chips, you know, they put them in -- It's all about extraterrestrials! E.T., man! That's the end game, the Illuminati and E.T., it's obvious! I mean -- Okay, it's so simple, see, like, Jesus was real, but they put an alien brain in there, and then the miracles, that was TECH you see? That was alien technology, isn't that obvious ..."
One thing that makes a rant a rant is that it does not stop when it has already clearly made its point. The speaker keeps wanting to drive the same point home, over and over. As the rant progresses, the speaker is running out of straightforward ways to convey this message, so the content is slowly getting sidetracked with more forced analogies and needlessly roundabout ways of saying things.
The speaker also does not leave any gap for feedback, as they are 100% saturating the conversation with the point that they're trying to make. They don't really listen to responses if anyone talks over them; and if they do acknowledge what another person has said, they do so without changing their own conversation topic (merely grammatically phrasing it as a response to what someone else said), immediately steering back into the topic they were ranting about.
Thirdly, as the rant continues, the speaker gets more impassioned. The specific emotions is contextual. Usually it's anger, or sadness, or obsession (in that descending order), but you can play around with different emotions here. The rant usually only stops either when someone forces it to stop, or when the increasing emotion becomes so large it derails the person's ability to talk any further.
The walls are closing in, I can feel them. They're painted a sickly green, the color of moldy cheese. They're dripping with slime, and it's trickling down my neck. I can't breathe, the air is thick with the stench of decay. The floor is sinking beneath me, I'm falling into a bottomless pit. Help! Help! Can anyone hear me?
The toaster is plotting against me, I can see it in its beady little eyes. It wants to burn my toast to a crisp, just like it did to that poor, defenseless bagel yesterday. I won't let it win, though. I will fight back with the spatula of righteousness! But first, I must discuss the philosophical implications of free will versus determinism.
My brain is on fire, I can feel it sizzling and popping like a pan of hot oil. The voices in my head are screaming, they're telling me to do terrible things. I can't shut them out, they're too loud! I can't take it anymore, I'm going to explode!
The colors are too bright, they're burning my eyes. The sounds are too loud, they're piercing my eardrums. The smells are too strong, they're making me nauseous. I can't feel my body, I'm floating in space. This isn't real, this can't be real.
"They're watching me," I thought, my eyes darting around the room. "They know what I'm thinking, they know what I've done. I can't escape them, they're everywhere. I have to hide, I have to disappear."
By using these devices and figurative language modules, you can create a character whose mental state is unsettling and disturbing, making the reader question their sanity and the reliability of the narrator.
The essence of an unhinged rant is that it's a non sequitur: The rant is not justified by the circumstances that led to it. This doesn't have to be incoherent, however! An audience will generally be able to follow cause and effect even if they perceive the situation differently and would make different choices.
This rant could be triggered in your character for any number of reasons; it's whatever makes sense for your story. The reason could even be that the person is bored, as is the case for many online trolls (who may not even believe what they are saying). It just has to be a reason that your audience does not relate to, even if they were in a similar situation.
Often this reason is paranoia. We all may have a little paranoia sometimes, but people who are very much hinged are able to dismiss it in the absence of actual evidence. A person who is not will connect the dots between all types of events, even things so small most people would ignore them, and make it all into a conspiracy:
Bad things were done on purpose for a specific reason by one or more people out to get you in particular (usually secretly). Your papers ended up on the floor because your one coworker is trying to sabotage you, not because the fan points at your desk.
Even when there really was some malice behind an action, an extremely paranoid person is likely to jump to conclusions about who (or what) to blame, perhaps on a connection as tenuous as getting a weird look from that person earlier.
Even otherwise neutral things may become twisted in the mind of such a person. Imagine thinking that the flicker of headlights (in reality caused by faulty wiring, or a car going over a bump) was actually someone trying to send you a message.
This overreaction is needed in some cases for the character to be considered unhinged instead of just pitiable. For example, if a character thought all their coworkers hated them because nobody said hi in the morning, the audience might see them just as an anxious or sad character. However, if they threated to put rotten eggs and hot sauce in their coworkers' food for that reason, it would be unhinged. (Doing so would also be a crime!)
Id say. Remember to give every single one of your mad characters a method. A logic of their own. Just because it doesnt make sense to YOU doesnt mean it doesnt naturally flow from A to B in their minds.
Play with writing a normal letter from a place of emotional desperation but trying to be as eloquent, earnest, honest and pushy as you can while remaining within the bounds of reason and decorum. Then switch the things that are important to the person writing the letter for utter madness. "Retrograde mercury will make my GF leave me and wake ctulhu up from his slumber deep in rlyeh". "If I dont click the lightbulb of my room 12 times in a row the demiurge will get me!
Then if that still doesnt sound deranged enough you bring in the chanting and ramp up the earnestness a little bit. "And of course the landlady doesnt understand that if I dont click the breakers on and off 12 times every night my GF will leave and ctulhu will awaken from his slumber in Rlyeh!- CLICK CLICK CLICK - "Koomba yhmy LOrdcumvayah!"- CLICK CLICK CLICK - screw her appliances, she can buy surge protectors but I wont let the priest of the old gods raise up to lay waste to the world, or lose gina". I mean, sure my example got wacky rather than deranged but you get the idea. Ramp up the earnestness but also ramp up the eloquence of the character.
The effect when you write your deranged character as a calm, collected person who talks about these things with the same energy, care and belief as a scientist who tells you "please, please, please, wear a mask and vaccinate". But they do so when talking about the secret font that can make any college paper an instant A+ by hypnotizing the teachers. Imagine that "I only need a drop of your blood in order to make a clone of you and use your biometrics to get into the science lab, but heres the plan. Meanwhile youll be in memphis for the science fair which you will obviously win and that will give you the perfect alibi. Meanwhile You-2 sneaks into the lab, steal the font. I disintegrate the clone and no one is the wiser. And I know what youre thinking, what if the clone and my best friend bond over my abscence and now the clone resents me because I get to be the science fair winner while he gets to be the criminal element that gets murdered. Dont worry I will take away the clones tongue before I jolt him to life so he doesnt get to mess with my head. So, when can I drop by with my bio extraction kit?"
3a8082e126