Oh man, one of my friends first-time DM'd. They intentionally told us all different versions of what the campaign was going to be, with the end result being they broke a cardinal rule of DMing; make sure you're running the same campaign as your players.
Needless to say I wasn't very amused when my wholesome non-combat character, made for a wholesome social campaign - who had not killed a single thing in three campaigns, was pitted against the God of Pestilence.
Our Dwarf barbarian is on 3 HP in a flimsy marketplace, 60ft away from the nearest party member. Our wholesome human bard is on 3 HP and has her face disfigured. My character, an elf rogue/cleric is outside a museum. The museum's front doors were broken by the God of Pestilence, and it is on fire after my character set a perfume fire to try and escape the God of Pestilence. I have 33 HP, and am standing next to the human bard. We are standing outside
during a blowout, which is a death sentence. The nearest intact building is 120ft away, however it is a residential area. If we are capable of surviving two rounds in a blowout, and the front door is not locked, there is a high likelihood the house is full of plant-horrors, things that used to be the people of the city.
Our only hope is a fourth player, who managed to avoid the infinite goblinsing (everywhere we went there was a horde of goblins) and God of Pestilence altogether, riding in on horseback to save us. He's got 12 seconds to find us and bring us to safety though, so it's not happening. Our DM thought we were being too dark by preparing our speeches for a last stand, and said there was so much we could do.
When the blowout triggers, portals open up to other planes from which these otherworldly horrors emerge. The God of Pestilence was only one of them. The blowout comes complete with environmental damage, and at the end of the blowout things emerge to grapple anyone outside, followed by people turning into plant horrors if the DM hasn't already described their suicide.
Afterwards the DM and I had a lengthy discussion. The DM kept saying things like "it was obvious it was a death God" - bearing in mind the only reason I knew it was a God at all was because I metagamed when the DM asked if any of our lvl 5-6 characters had more than 20 CON, and knew he had sicked a CR26 creature on us, and that "there was so much you could do," with his "obvious solution" of standing on a pedestal to defeat something that auto-hit us just by being in
proximity, moved twice as fast as us and had unknown capabilities. Twice I had to rules lawyer like an absolute disgusting bastard just to stop the God of Pestilence killing my teammate twice (it "demonstrated" new abilities to get around the traps I and the bard set. I use the word "demonstrated" lightly because I'm sure the DM just kept making up rules so we couldn't avoid the God any way other than the way he wanted).
I've got a lot of work to write up but I'm gonna do a full writeup of this horror story if anyone's interested. Jesus what a nightmare