Take away plot armor, what becomes a guaranteed death in your favorite series

That dragon balls aren't plot armor they're a Deus ex machina or muggufin that can be spammed to the cast of DBZ with little to no consequence, the DB cast has in fact died MANY times each specifically because they don't have plot armor

I don't watch children's cartoons, nobody has plot armor in my favorite series.

They don't need plot armor in moe garbage you're right

I'm an amateur writer (aka a bad writer) and plot armor is a weird thing to work with. On the one hand you kinda need it to tell the story sometimes and on the other hand sometimes fate just works that way. Weirder shit has happened in real life, I guess.

I'm working on a story where the villainous antagonist is overpowered as fuck compared to the hero protag and only doesn't kill her because he doesn't see her as a threat. By the time he does she's gained the upper hand on him and can defeat him. Is that plot armor or what? Like I said I suck at this kinda thing so i'm learning.

Plot armor is way more about execution than it is about the premise. Yours is fine but there needs to be a believable reason why the antagonist wouldn't notice your hero getting stronger before the point where he can be defeated, especially if they've had enough confrontation for him to both acknowledge she exists and write her off as not a threat. That reason needs to fall in line with both his and her personalities, motives, and circumstances, too.

Tell us your fave series and we will find a way to destroy the plot armor

Luffy, Natsu, Maka, every Jojo, Kenshiro.

If villain incompetence counts as plot armor, Touma.

That's a form of plot armor, yes. But you can mitigate it depending on execution and how believable you make the villain/cohesive for their philosophy. So say he doesn't gib the MC because he doesn't view her as a threat. For one, you probably want to have them interact as little as possible so as to not stretch the disbelief. Say he lets her go from some initial encounter even though he could have killed her there. Next you want it to be consistent. If he let the MC go for not being threatening, he should do that generally. If you later have a scene where he murders a child or defenseless puppy or something it clashes with the belief that someone so ruthless would have let the MC go. And then you need to have the MC believably sneak up on him. If she's ruining some plans he has every week yet he persists in not dealing with her as a threat then he becomes a Saturday Morning Cartoon villain and to readers will come off as an idiot.
As a caveat to some of the above, you could escalate stakes by making him realize he was a dumbass. So he lets MC go at the start. Later he lets other people go to show consistent character. MC starts ruining plans of some fashion but other matters need attending to so he can't directly go deal with her. However as a result of this, since he realizes his mercy has caused his current problem you show him being ruthless and now the next time he meets the MC he's not going to let her go just because and if they need to encounter but break up where neither dies you'll need some other driver to do that.
Just for example, I don't know the plot of your story.

It's the protags debut story and it's about her realizing that despite her own enormous power there are bigger and more powerful threats to her than she initially realizes since she's a big fish from a small pond. So she ends up defeating him with the power of nakama but this first story is the first step to her journey to becoming stronger to defend the Earth from unseen powerful enemies down the road.

So this villain is kind of a sociopath narcissist. He believes the people of Earth are so beneath him and so weak they could never be a threat. His first interaction with the protagonist is toying with her to prove his superiority over her because her father is this legendary powerful figure in this setting. He tests her and finds her wanting and delights in this revelation, leaving her alive to witness the destruction of her home and and use her death as a message to her father somewhere in the galaxy.

It's almost a psychotic way of taunting the protags father and his superiority complex and toying with them as he carries out his plans (which are elaborated on in a future story) is icing on the cake when he discovers she can't keep up with him.

In the end the humans of Earth alongside the protag catch him off guard with a surprise that leaves him vulnerable to defeat by the hero while still remaining quite dangerous despite the massive handicap he gets.

It's a big nakama with the way his defeat is handled.

It really is a planet level apocalyptic threat too. The final fight gets progressively crazier until the surprise double team with the hero on the defensive just barely pulling through.

His hubris and the time it takes to set up his plan is what helps the main cast defeat him. If he had viewed any of them as a threat from the start he would have went on a genocidal rampage from the start instead of goofing off.

Does that sound shit or what? When he gets handicapped in the final fight he goes full try hard murder machine.

It sounds fairly typical for essentially a starter villain in anime or JRPGs. It's not bad inherently, but it has been done a lot and it will depend a lot on if you can make either the villain, the hero/companions, or their interactions interesting. As an example for anime, this sounds like the kind of set up Trigger could make fun and exciting through visuals and charm even if the substance has been done a lot before. Doing it purely through writing is harder, obviously, you can't cheat emotions with pretty pictures or music.

Oh yeah, way ahead of you. The characters and interactions are one of the most important parts of the story in my mind. I realize it's kinda tropey but I dig that, and in this case it's a means to an end for the characters and their relationships and further stories.

It's also setting up this versions of late 90's Earth to the crazy stuff going on in this universe.

I don't know the length of the story you're planning to tell here, but I think a trick here will be making such a character a believable "main" villain at least for whatever length of story this prologue-ish thing is. This villain archetype usually gets whacked nearly as a tutorial boss and other long lived examples come across as really, really stupid.
Dio in Stardust Crusader's sounds like a similar type character that is the main boss while also being generally loved. He is a massive dumbass though.
Lucifer and the Biscuit Hammer's Animus sounds also similar, and is similarly a planetary scale threat. In his case he's imposed rules on himself, well agreed on rules with his sister, that restrict his actions greatly until the end.

>father is legendary figure
>wants to destroy Earth despite thinking humans are so beneath him that they don't matter
>wants to kill daughter specifically but doesn't bother keeping an eye on her at all to make sure she dies with Earth instead of fucking off somewhere else
>Earth is technologically advanced enough to BTFO big space threat but not enough to have obvious escape routes that villain and cast probably both ignore since it takes place on/around Earth
>not at all considering this legendary figure (realistically on par with him or better if he has such a hateboner towards him) could come to daughter's rescue
Even for an excessively prideful and arrogant character, this isn't that believable unless you're very careful backing it up with context. If nothing else, he should at least consider the father a threat and keep an eye on the hero to make sure she stays put.
It's probably okay still if you're going for the cartoony character-driven JRPG style, but if you want to make serious considerations for worldbuilding keep your plotholes in mind.

Sensei would be the first to die, obviously

So the villain of this first story is not a main villain for the series. He's powerful, cocky, sociopathic but not the main main villain. He's the first boss.

Destroying the Earth is important to the larger overall plot, the villain of the first story is just excited to get the hero's fathers attention. The Earth is important to him as well but also because it's his daughters home and supposed to be her safe haven while he is away due to the larger overall story for the series. It was also once his home, he has family, friends, loved ones and history with the Earth.

The villain is doing a job he was sent to do by someone else but he's stoked to do it. They want to hurt him.

And it is absolutely supposed to be cartoony-JRPG-shonen tier. That's exactly what i'm going for all the way. I want it to be like escalating hype.