The heavy would be Palpatine because he's essentially the main reason why the sequel trilogy is a thing. He created Snoke and used him to control the First Order and manipulate Kylo Ren into the dark side of the Force.
The big bad is something that depends on how you view these stories being told. If you view the trilogies in general as separate arcs, then Palpatine would be the big bad because he's pretty much the most reoccuring villain at this point. But if you're specfically referring to the sequel movies, then that would be Kylo Ren and Palpatine would just be the bigger bad as usual.
You have everything mixed up. The Big Bad is the villain who causes the plot, the Heavy is the villain with the most influence over the direct plot. Without a Big Bad there would be no plot, but without The Heavy the plot wouldn't affect the Hero. The two can overlap, but they're different things.
If we look to the example of the Original Trilogy, the Emperor is the Big Bad because he ruled the Empire and controlled the Death Stars, while Vader is The Heavy as the most prominent direct threat to Luke. He causes the direct plot to occur with his pursuit of Luke, but it's the Emperor who is the source of the problem by ordering Vader to bring Luke to him. If that makes any sense.
Nowhere is it stated that the Big Bad is the cause of the series. The Big Bad is the prominent, most reoccurring antagonist that appears throughout the series, but that doesn't mean they're the reason why the story exists. That's what the Heavy is for. The Heavy is the reason why the story exists to begin with and if you take that villain out, the series wouldn't exist.
Also it explicitely states on the Big Bad page that the Big Bad is "the direct or indirect cause of all troubles for most of the story if not the story as a whole." So yes, the Big Bad is the reason why the story exists, they're the cause of the problems in it.
The Heavy is simply the villain with the biggest role in the plot. They set the immediate action. The reason why it specifies they're the cause for the series to begin with is because they're the reason the plot touches the heroes.
If they're referring to the immediate plot then that's something that needs to be clarified and some of the villains there need to be removed.
Vader's already been the Big Bad on this wiki for awhile now, but now that you brought that up, that would make Palpatine the heavy then because he essentially caused all the events in the prequel trilogy to occur.
The reason why I'm saying this is because I'm certain Jester in particular agreed that All For One was the heavy for MHA while Kaguya (and to an extent, Black Zetsu) were the heavy for Naruto.
The Heavy is just for meaning the story as a whole, basically it boils down to if the story could happen without them or not. If easily replaceable plot wise then they cannot count. All For One ultimately was the Heavy as without him then One For All basically wouldn't exist nor All Might etc.
By the logic you are espousing, Darth Plagueis should be The Heavy of the Star Wars series since if he hadn't trained Palpatine in the Dark Side, he wouldn't have corrupted Anakin to it and the entire saga wouldn't have happened.
Actually wait no, Darth Bane would be The Heavy because if he hadn't created the Rule of Two, then Plagueis never would have become a Sith and taken Palpatine as his apprentice, and Palpatine never would have learned the Dark Side and used it to corrupt Anakin.
Actually wait NO. By your logic, Ajunta Pall, the First Sith, referenced only in EU material, would be the Heavy since if he hadn't formed the Sith, none of the events of almost all of the Star Wars movies, TV shows and EU materials would have happened.
Do you see the problem here? You've effectively turned The Heavy into just a clone of the Bigger Bad category. The Heavy should be for the villain who has central focus in the plot, not necessarily the overarching cause of it.
I can't say for certainty on Tomura being The Heavy here or not due to not being an expert depends on how much of the story could theoretically happen without him as technically there can be more than one Heavy just extremely hard. I think most confuse it for just being another word for a central antagonist or Big/Bigger Bad when not the case as even a relatively minor villain can count ex: Of Batman the Heavy isn't Joker or a major Supervillain but rather Joe Chill because story wise irreplaceable as he's what made Batman possible.
The Heavy is its own thing that can overlap but not always it's simply irreplaceable character who without its impossible for the story to exist. Star Wars got a bit convoluted to but movie wise it's Palpatine as its implied he was the one who caused Anakin's creation from what I've read. Bigger Bad is the boss of the Big Bad or unseen manipulator of the series, some count others do not. The Heavy doesn't exist in all series either but the categories are separated for a reason (arguably Vader as well). As said I don't know for sure either way with Tomura but can easily explain why All For One counts as one.
The fact that you went so far as to state that Tomura Shigaraki, the MAIN VILLAIN, wasn't important to the plot of My Hero Academia proves to me that you can't be reasoned with and that there's no way I can change the warped definition of The Heavy you have. I'd rather focus on other projects rather than continue some stupid edit war over things that should be obvious.
I just simply want to hear what some of the other admins have to say so things could be clarified and ultimately reach to a conclusion, before anything can be changed. Because if what you're saying is true in regards to the Heavy, then the category needs a cleanup as some villains do not belong there (i.e. Joe Chill and the Burglar to name a few). There's no need for the hostility.
The first sentence of the Heavy category page is "The villain with the most influence over the plot, the setting of the story and even occasionally the life of the protagonists". Beyond creating One For All, All For One never really interacts with Midoriya or any of the other main cast. His primary role is teaching Tomura and providing him with the resources to battle against the heroes. You remove All For One from the immediate plot, you still have Tomura masterminding attacks against USJ.
Also, the "Heavy" isn't a term that originates with this wiki or TVTropes. It actually comes from theatre terminology and was often used in television production to describe the role of the lead villain, the one with the biggest role in the plot. The reason why it's called the "heavy" is because, as the lead villain, they would often have the most lines, and thus the "heaviest" script.
Ok. I'm willing to at least let Tomura be under the category and remove All For One from it. And depending on what happens here regarding this matter (if more admins do give their input or what not), I can help you clean up the category determine which villains belong and don't belong under it.
The thing is if it were just the central villain it'd be practically another word for Big Bad. I get your frustration but the issue is without All For One the setting would be entirely different to where Deku never would have the chance to be a hero. As said be I am not sure whether or not Tomura could qualify but even that first line indicates irreplaceable but I lean to it being a rare case of both counting.
The overall role of the Heavy can vary but the impact of the setting is irreplaceable. Joe Chil being the best example as while Joker and others might play a big part in the present they aren't individually irreplaceable as stories can realistically happen without while Joe Chill is what drove Bruce to become Batman thus allowing the series to exist, similar with the Burglar in Spider-Man. Palpatine for example counts as he is basically the one who manipulates events that allow all the trilogies to happen. Most Heavy's overlap with the Big or Bigger Bad but not always as not all them are irreplaceable towards the story or setting.
If I sound like an ass I do apologize as I'm just trying to help elaborate what the category is meant for but unfortunately abuse has caused confusion on all sides.
Okay. I just wanted to get Tomura under it, since he's the one driving the plot.
Sorry if I was rude or pompous earlier. I've had a long day and unfortunately that seeped into my editing. From now on though I think it would be better if we'd just take this stuff to the message wall instead of edit warring about it.
And yeah, a lot of this seems to stem from confusion on how to interpret the Big Bad and The Heavy category pages. I've even seen the admins contradict themselves on this, so it really should be cleared up. Based upon our conversation, it seems I was mainly focusing the first sentence while you were going with the Note at the end.
No, no. It's ok. Sorry to hear you had some stuff going for the day.
I apologize if I was coming across as unreasonable because that wasn't my intention, I just wanted more input on this since it's practically become clear that there is confusion on how this category works. I agree though it's better to have these things discussed out before doing anything on the articles.
As for the category itself, like I said, depending on how this goes, the category may likely need a cleanup.