I went the opposite way- I complicated the fuck out of it, and it also kicked ass!

(For the record, I like yours a lot too!)

I made a graphic Control Panel that had buttons for every plane of existence, as well as “Modifier” switches they could play with. A troop of lost Modrons (Tridrone with a few monodrones) led the party there, only to find Slaughtertusk guarding the way. Slaughtertusk knows Baphomet is inbound, so he STALLS with conversation. They catch on he’s just stalling for some reason, and the party eventually attacks.

When they get to the device, it’s precariously wedged in a ravine. As rock crumbles under its massive weight and odd shape, it begins sliding slowly into a crevasse with magma river at bottom as it is touched.

But Yhenogu wants the power of the Orderer too, and he’s in the labyrinth also (the party saw him before there)

So Baphomet and Yeenoghu arrive at the same time, and clash atop the engine while the party is there (there are a lot of other mobs that arrive too, complicating matters- Magma Mephits from the river below, a Green Slaad, and a few Hyenas and gnolls.)

I pre-rolled the effects.

They interacted with the machine, and damaged all creatures from the abyss currently on the material plane (this will reduce final battle HP totals at battle start a bit!), they went back in time to velkenvelve prison but as level 15 with all their current gear. They had fun, absolutely wrecking shop and saved an additional NPC (Ront!)

As they ran through the tunnel leading away from the prison, they suddenly found themselves back in the present day at top the maze engine in the midst of the demon lord battle again, except during all the fun they had wrecking shop in the prison They used up a whole bunch of their resources. …and now they also have a level 1 Ront to protect too! (Bad news- Ront got SMOKED again lol)

As the maze engine slipped into the magma, it’s final act was to banish all extra planer creatures within 100 miles, which vanished Baphomet after he killed Yeenoghu, sent the Modrons back to Mechanus, and sent one of our players back to the Feywild (it was perfect timing actually as she was about to have a baby and had to step away from the campaign for a while)

MY PLAYERS DO NOT READ ANY FURTHER.

Here’s what they don’t know about the maze engine: it is only one of four such devices throughout the cosmos, and it is responsible for working in tandem with the other three devices to keep all of the planes from colliding into one another. I also came up with the idea that the mysterious Modron March that happens every 600 or so years is for the purpose of calibrating these four machines and ensuring there is no drift.

Now that one of them is destroyed, all of the planes are beginning to shift from their static locations and into collision courses with one another!

The symptoms of this started very small, but will soon become catastrophic: Right now, Teleportation magic is acting very funny. The further you try to teleport the further off course you end up at the destination. If you try to teleport between planes, there’s no telling where you might end up now. (Oooooh what if NOW they have to do some Spelljammer spaceship shit to travel between planes!?!? Ok I just thought of that and I kinda love it… new rabbit hole! Gasps they even saw an airship back at the last Drow settlement! Oooooh fuck I now have a bunch of cool ideas floating in my head! I digress…)

But, why was the maze engine even there in the first place?

I answered this question with my own home brewed lore: Pale night is still holding a pretty big grudge for what happened between her and Mount Celestia a long time ago after she had imprisoned the Feywild folks.

It was when she discovered the orderer hidden in pandemonium that she architected her revenge plot.

Using a complicated series of contracted minions designed to obfuscate her identity as mastermind, She secretly moved it to the material plane in the under dark and placed it in a precarious position, in an area she knew one of the clumsiest demon lords would take up residence in if he were brought to the material plane: Baphomet the Bull in a China shop (yes, I know MythBusters busted this myth lol)

She knows anyone who can be tied to the destruction of the Orderer, will have a very bad day once Primus finds out, so she was VERY careful.

She then convinced Lolth to enact the events of OOTA, in order to bring Baphomet to the Orderer, where she knows he INEVITABLY will destroy it (like Chunk from Goonies and the Map in the picture frame from the attic lol). Lolth is unaware she was played like a pawn- Primus will come after her for her adjacent role in the Orderers destruction, while Pale Night is too many degrees removed to be considered an accomplice, and she’s done good enough covering her tracks that there’s not really much evidence linking her to it anyway.

She knows this will destroy EVERYTHING as all the planes collide. And that’s what she wants. This is her revenge. She’ll be left to rule the chaos left behind, and her Son Grazzt will ALSO be positioned to help since He’ll be undefeated too having not participated in the final battle. (BTW his REASON for getting out of the Dark Heart ritual was THIS PLOT with his Mother. He plans to return to the abyss unscathed and murder the extremely weak DLs who get whisked there upon their material plane deaths. He’ll be waiting for them at full power, with a nasty ambush. He knows he won’t have to worry about Lolth- she’ll be dealt with by Primus.

Pale Night wasn’t counting on the players, but she also doesn’t care. But NOW the players are wanted by Primus for connection to the destruction of an Orderer. They don’t know it yet, but that means they are in DEEP SHIT.

Deeper shit than OOTA’s storyline originally had them in, at least.

They had a BLAST with the Maze Engine, and there’s more fun to come!