So, to preface this story, I had been in DnD for only a few months, only attending a few sessions with this group with a different GM. However, I have many years of roleplay experience, world building experience, yaddi yadda.
So, I decided to create my own world. I fleshed out a pantheon, several kingdoms on several different islands. I created the host of primary NPCs, and a few secondary NPCs that could be slotted into whatever role I needed them in.
I went to my potential players and asked if they'd prefer a combat heavy campaign, or one focused around roleplaying. An example I used was talking your way out of an ambush instead of cutting your way through it.
They all said they wanted roleplay over combat, except for one player.
The premise of the hook? They were all from our world, set a few decades in the future. They worked for a massive global corporation and were no-name cogs in the machine. They were sent on a mandatory vacation (The corporation gives you a 1 week, paid and mandatory holiday to cut down on their stupidly high suicide rates of employees).
They were staying in the hotel on the company owned resort when it was bombed and they all died in their sleep. They were resurrected and given powers, then shipped to the fantasy world for various reasons. Despite being overpowered by lvl 1 standards, the Gods didn't try to make them be heroes, the Gods didn't care about them.
All the Gods asked for, was that they didn't lead a global genocide against anyone.
So, they wake up in this fantasy world, with their new appearances and powers. A group of fellow level 1 adventurers past them in the forest where they had awakened and gave them starter, basic lore and mechanics of the world. They learned this kingdom was ruled by an nobility structured around giving the rare powerful magic users nobility titles, however, anyone could ascend the ranks with enough skill as it was a meritocracy.
The party instantly, and without reason (In my eyes), developed a hatred for the idea of nobility. They went to the town that was considered the beginner area of the main kingdom.
There, they met an NPC named Karsik. His purpose? I created him to be an overpowered friendly NPC that could be called in to support them when they needed it. However, he wouldn't step in too far. The few combat encounters he was in, he only provided the bare minimum support that they wouldn't die from stupidity. They were overpowered level ones, but were still level ones. Everyone in the party was immediately suspicious of him, save the Barbarian named Rolf, from Accounting.
One of the party members, their mage Cero, from Security, checked Karsik for murderous intent with a magic spell. Karsik responded by looking back at Cero and tilting his head, "Alright back there?"
More red flags for them were raised.
They got to the town of Hero's Claim, and made their way throughout, finding all the places before getting to the Adventurer's Guild headquarters. There, they tried to join the Guild, but their Paladin, Addy, a Lawyer for the corp made them refuse it. Despite the contract that was put out was that they couldn't commit crimes against fellow Adventurers and that was it.
So, in order to keep them connected and getting quests (As Adventurers picked up quests from the Guild), Karsik brought them on a quest of his own. It went well, and it was used as an excuse to bring the party to the Baroness who ran the town since Cero had incredible potential as a mage, and everyone in the party had potential to be future heroes.
I made it clear that the Baroness clearly had a solid control over everything and was beloved by the people of all status. They still were suspicious of her and took her up on an offer of a nobility title for Cero, as well as one for the party rogue and face of the party, Alice, from HR.
They were given a small castle to use as a base, and a small village for income. They tried to find rebels living in the country, but outside of tiny bandit groups who were "totally anti-government" there was no rebellious movement. So, the party went about adventurering in the name of Alucia, the primary kingdom.
There, they manipulated and lied to villages to develop a rebellion that when launched, crippled Alucia financially from having their farms and mines left unworked. This led to famine, disease and a civil war.
They used the civil war to justify slaughtering an entire noble's family from the head of the household, to their 4 year old daughter. All because they were nobles. At that point, I tried to clarify if they were playing evil characters, as their sheets said Chaotic Neutral (I know now that Chaotic Neutrals are usually just the way to avoid the evil tag)
They denied being evil characters and went about their purge of the government. They even managed to turn the rebellion into an anti-nobility focused one. Of course, it's primary cause was destroying the nobility. Which just so happened to be mostly mages. So mage hatred skyrocketed among the commoners. Can you see where this is going?
In the final fight, they were against Karsik and the Baroness, both significantly higher levels than the party. A mechanic I developed for the campaign, under guidance of the GM from the previous game and permission from the players, was a Level Break. Where, at max level, you could go past it and continue getting stronger. More spell slots, more health, better stats. Karsik and the Baroness used this, and the party did as well but were still weaker.
They managed to kill the Baroness but found their poisons and magic useless against Karsik, who, after the Baroness was killed, stopped fighting back. He revealed he was an undead now, a former Hero from the party that killed the Demon King 100 years prior.
He laid out that they had taken the healthiest, strongest, and happiest kingdom and broke it down. Their nobility rarely had corruption, as only those suited for power could have it. Their people never starved and disease was rare.
He used a teleportation scroll and left the party in the bloody, damaged keep. The last group of soldiers came into the throne room and Cero used a powerful spell to wipe them all out. Only to have a rebel see him do so.
They expected to be treated as heroes and become the new lords of the land. They went to sleep that night and were all stabbed to death in their sleep by the rebels.
The players wanted a rebellion, but never provided roleplay for how it was ran, or what it's goals were outside of starting it and making them hate nobility. This fragmented the rebellion and left the land open to invasion by a truly evil kingdom.
Their souls were damned for eternity to the daemon realms to be punished for their evil deeds and the campaign ended, after 4 sessions.
And I was never treated the same by the players. Rolf, the former GM, is the only person I still talk to and I haven't been able to find a group again after that. I lean towards playing true neutrals or good characters yet all the players I've met, save Rolf, played evils.