[Brainstorming] Greek (Olympus) One-Session Adventure for lvl 14 PCs

[Dralnu]

We're getting to the end of a long homebrew campaign, but before the party enters the final dungeon, they must make one last stop on Olympus, where they have been tasked to release an avatar of Grazz't from its imprisonment inside the Temple of Zeus. I want to make a memorable trip for the players steeped in Greek mythos while keeping things short and tight enough to finish in a session.

The group are level 14: Champion Fighter, Open Palm Monk, Diviner Wizard, Thief Rogue.

Due to events in the campaign, the entire multiverse is under siege by basically a zombie apocalypse. Countless numbers of souls that for whatever reason winked out of our reality and were banished to the nothingness of the Void, these Vestiges, are now returning to reality due to a breach and are inhabiting corpses of the newly dead.

Olympus is no exception. When the PCs arrive, they see a city aflame, its people desperately trying to fight back these vestiges, but every person that dies rises as one of them. (I would assume the gods themselves have manifested to deal with this issue, but I have yet to figure out what is either stopping them from saving their realm or is powerful enough to challenge them in a fight.) Amongst the vestiges are minotaurs, harpies, and a medusa, possibly other villainous Greek monsters. The PCs can involve themselves in saving the city or they can head straight towards the Temple of Zeus.

The Temple is currently attended by a few priestesses and a guardian. I'm not sure what the guardian should be, but ideally I would like it to be something that cannot be chain Stunning Strike'd to death, as the monk has a habit of doing that against pretty much every "boss fight" I've thrown at them. I was thinking an Androsphinx, but I'm no good at thinking up riddles, and it's also vulnerable to Stunning Strike spam.

[Kane0]

Well obviously an ornate bronze golem crafted in Zeus' likeness is the guardian, furiously frying anything that comes close to his current nymph sidechick with lightning bolts. He may well just assume that the PCs are here to stir up additional trouble on top of the current Vestige apocalypse and resorts to lightning first, words later.

A bronze golem would be immune to stunning and a couple other shenanigans while also being a physically tough opponent to deal with. Add in a lightning bolt attack and the ability to heal from thunder/lightning damage plus some legendary and/or lair actions and you're pretty much set!
Perhaps it'll even go berserk if the Nymph gets killed, going on a rampage.

[Felvion]

Kane0 described Talos (https://en.wikipedia.org/wiki/Talos). It was supposed to be a guardian golem so it definately fits your needs thematicaly.

[Kane0]

Unwittingly, but yes. It didn't make sense to have an aspect of Zeus present from the description given, so I picked the best representation of him given the culture, a grand statue. And what better material to use than Bronze? Thus Bronze golem with Zeus-like abilities and tendencies.

Edit: Marble makes a good runner up though, both are pretty famously Greek.

[Dralnu]

Great idea. Looks like I could start with Iron Golem and it would only need minor tweaks to fit, just switch the resistance from fire to lightning and add an extra lightning attack.

I had also considered a Planetar as a possibly cool moral dilemna, but it's not based on anything Greek and sadly it would fall pretty quick to Stunning Strike spam. The golem has no such issue though.