Ok so I just got into D&D last year (2019), I joined in the middle of a campaign that was being held over Discord and roll20, and using 5e with some homebrew rules. The group I joined was fun and we all had a blast, even ending the first campaign, and after a few months of one shots, The DM started a second campaign taking place in the same world as the first one just taking place 15 years later. The party had 5 players, a changeling sorcerer (Me), a half elf bard, a dwarf fighter, a hobgoblin cleric/wizard, and a human bard/sorcerer. The story of this campaign was great, though as you could see but the party make up most of us were squishy spellcasters, the only front line fighters being the dwarf and the hobgoblin, so they would always take up the front as the rest of us supported them from the back. We were on our way out of the underdark when all this happened, as we were heading to the surface, we came across a giant spiders web, so after sometime, I cant really remember this part of the campaign that well sadly, we had to fight some giant spiders. Not really a tough task…till my sorcerer threw a fireball in the web, burning it and revealing that all the giant spiders we were fighting were the babies of a spider that took up 6×6 squares. So yeah, for anyone who knows how the size system works in 5e, that meant that this spider was around the same size as an ancient dragon! But through a lot of lucky dice rolls, we were able to kill all the spiders, even though the player who controles the dwarf couldnt make it. Buuuuut, that wasn’t the moment the DM tried to pull a TKP…that came later after we made it to the city the dwarf in our group came from. We find out that last time the dwarf was here they got into trouble. So for us to be alowed to pass through the city with no problem’s our group agreed to take care of a problem the city has had in the mines. We thought that we would get a long rest before they would try to make use do this job….buuut any time we tried to ask for where a tavern was by our guide, he would seem to brush us off, even after one of us, I don’t remember who, got a high roll to find out…as the guide seemed to wander off, as the DM tells us that because we don’t want to follow him he was going to leave us, I was still some what new to D&D at this point, but even that kind of set off a red flag in my head. The reason we wanted to take a long rest was because we didn’t get one after fighting all those spiders, and most of our spell slots were used and we had lost some HP. I should tell you at this point we were level 9, the DM liked using the monument system to keep us all at the same level and to keep people from just killing NPC’s for no reason other than to get EXP. So we caught up with the guide, and he led us to the mine, after going down in there we started to follow the caves, but as soon as we got there, the DM had all of us roll initiative, needless to say we were all stunned as we didnt understand as why they had us do this, as we couldn’t see any enemies. So as we kept going deeper into the mines, as the dwarf kept charging forward, the character just wanted to die a glorious death in battle so they were normally going head first into battles. As the dwarf kept pushing forward, they came across a room that had broken boxes filled with smashed potion bottles, and a goddamn neothelid in the room!! Now I know some of you are thinking “Oh a neothelid for a level 9 party with 5 party members, that shouldnt be so bad”. Normally it wouldnt be…but we had lost some HP and spell slots in the last fight and we couldn’t take a long rest before doing this job, and the DM never told us why we couldnt. Also, I should bring up that this DM did like to tweek the states for enemies, to make sure no one would cheat by looking in the book, and to also make fights a bit harder. And for this fight, because of all the potions the neothelid was in, it got more than 1 turn per round, and when I say that it got 4 TURNS PER ROUND!!! So a fight started as the dwarf was the first to find the neothelid…and the neothelid got to move first and swallowed the dwarf, so he was inside it for the whole fight as he kept failing to get out. So for the whole fight our only main frontline fighter was the hobgoblin, who had only 1 level in cleric and 8 in wizard. Things were looking like all of us were going to die at this point….and it got worse as the neothelid, used a spell it knew, and the DM rolled to see if it would use the spell, and on who…and the spell got used on the hobgoblin, and the spell was feeblemind. For anyone who doesn’t know, this spell if the targeted creature fails the saving throw, its Int. and Cha. gets brought down to 1. So the hobgoblin rolled to see if it would pass the save…and got a 3 on the dice. This is were things got really bad, because now our wizard couldnt use any of their spells from the wizard spells they knew. So at this point we all believed that we were going to die, and I could kind of swear that the DM sounded happy with everything, even though the DM and hobgoblin were a couple in real life. But, the player of the human in the group realized that they had a 4th level spell slot, and used it to cast polymorph on the now dumb hobgoblin, and used it to turn them into a T-REX! The reason why the DM allowed this is because in our first session in this campaign, we all started at level 6 or 7, we faught an undead t-rex, so the DM couldn’t say we never saw one before as we kind of did. So, my changeling and the human hid as the t-rex ripped and ate the neothelid, as the half elf helped a bit. But in the end our group killed the giant worm, the dwarf popped out from its neck, upset that they didnt die in that fight, and my character looked in the room the neothelid was in, and saw a giant purple thing just pulsing on the other end of the room, and my character not wanting to take any chances, used their last highest spell slot to throw a fire ball over there, making sure to burn that thing and make sure nothing else some how comes from it. That session ended with us heading back to the city, knowing we would need to find someone to fix the hobgoblin, but the whole time after we won that fight, the DM just sounded defeated, almost like we did something to upset them. The next week the guy playing the hobgoblin in the campaign ran a goblin one shot as most of the players couldnt make it, and it was at the end of that one shot the DM said they were ending the campaign as they were getting bored of D&D 5e and didnt want the story to suffer. Looking back it just feels like they were trying to push a TPK on us to try and end the story so they didn’t have to tell us that, as when they told us they made it sound like they were only taking a break for DMing, but 2 or 3 months later they closed the discord server. I had known that DM for sometime by then and got the feeling that they just didn’t want to hurt anyones feelings by saying that they didn’t want to DM any more, but it would have been better that they were forward with it instead of doing what they did.