D&D General Help me build a mini-campaign: The Mindflayer Empire returns from the far future

[NotAYakk]

Oh, one more fun thing you can use exactly once. A future copy of a PC arrives and helps them. (for extra fun, a future copy of a PC broken by mind flayers arrives and hinders them, possibly via deception; that should happen 2nd mayhap).

You want this to happen once, because it foreshadows the PCs themselves doing it at the end of the plot. And only once, because it sort of steals player agency. That PC lived through a variant of the campaign where the PCs lost (or didn't win good enough), and has come back to boost the PCs somehow. They should have a very limited lifespan for some reason, so they don't help too much, but they should provide heavy spoilers for the next thing the PCs do.

Also, the mind flayers should taunt the PCs with "we are inevidible" when they are losing. Especially if there is a armor artificer.

Also, enslaved future copies of NPCs! Especially long lived ones, like liches or elves.

Oh, an enslaved god (from the future), driven mad, and rode by a huge intellect devourer, visible through a hole in their head. Maybe with a bio-cybernetic limb. Possibly one a PC follows. Reduced from godhood, but still a power to be reconed with.

 

[Levistus's_Leviathan]

I'm actually doing a campaign with a similar theme. It's a spelljammer campaign, where the low level villains are Neogi, but it is eventually revealed around level 7 that Mind Flayers are actually controlling them to accomplish their own goal. The players find this out by having to kill the leader of the Neogi Inter-Galactic Hierarchy (NIGH for short. Yes, the name is just for the acronym. In my spelljammer, the factions love using acronyms) and the neogi has an Intellect Devourer inside it, controlling the empire.

So, they find out the Mind Flayers are somehow involved, but already have time travel magic, by way of Time Crystals and a Time Staff that they stole from a time-traveler they killed (with stats of the Eonic Drifter from Tome of Beasts by Kobold Press). They discover that the Mind Flayers, when overthrown by the Githyanki and Githzerai actually didn't completely collapse. Instead of being wiped out from existence, the rest of the illithids fled to a crystal sphere that they closed off from the rest of the multiverse, all "hibernating" in the until the time came for them to reclaim their empire.

(The Gith knew that they actually didn't destroy the Mind Flayers, and instead only dealt a large blow to their masters. The Mind Flayers took many Nautiloids, Squid Ships, and other spelljamming ships to escape, hidden in the crystal sphere in which they currently reside. The Gith didn't tell anyone of how they didn't actually destroy the Mind Flayer empire, like they claimed to have done, because they did not want to seem weak, and if the others knew, there would be many other negative implications. The Githyanki wanted to seem strong, while still preparing for the day the Mind Flayers returned, Vlaakith is the only one alive that knows why they're preparing and ramping up their forces, but she's preparing, nevertheless. The Githzerai know that they are returning, but are awaiting for their return, and believe that Zerthimon will come back and bring their salvation.)

So, when the players discover all of this, they're going to have access to time travel, be around level 15, and know the plot of the Mind Flayers. They are planning on coming back when the gith are at their weakest, coming to decimate the multiverse and reestablish the empire. In this campaign, when they figure all of this out, they're going to have a date. This date is when the Mind Flayers will come back, and whatever they try to do, the most they can do is delay the return of the mind flayers. They will have to try multiple tries to keep the multiverse from being destroyed by mind flayers, probably with full-on assaults against the mind flayers, trying to unite the multiverse against the mind flayers, and stuff like that. If they try this route, they will lose, over and over again.

They can try other tactics, like banishing the crystal sphere to some other place and severing its ties from the multiverse, or something like this.

I don't know if any of this would be relevant to your game, but I just wanted to share this in case you want to take any inspiration from this.

 

[Eltab]

For other tech ideas, might want to check out 2e Mongoose Traveller. Also, imagery from Avengers Infinity War comes to mind - especially the last battle. Perhaps give the PCs a way to gate in allies when all hope is lost, similar to that scene...

How good is your Traveller lore?
The ally gated in is Grandfather / Yaskoydray.

 

[Urriak Uruk]

Oh, one more fun thing you can use exactly once. A future copy of a PC arrives and helps them. (for extra fun, a future copy of a PC broken by mind flayers arrives and hinders them, possibly via deception; that should happen 2nd mayhap).

You want this to happen once, because it foreshadows the PCs themselves doing it at the end of the plot. And only once, because it sort of steals player agency. That PC lived through a variant of the campaign where the PCs lost (or didn't win good enough), and has come back to boost the PCs somehow. They should have a very limited lifespan for some reason, so they don't help too much, but they should provide heavy spoilers for the next thing the PCs do.

Also, the mind flayers should taunt the PCs with "we are inevidible" when they are losing. Especially if there is a armor artificer.

Also, enslaved future copies of NPCs! Especially long lived ones, like liches or elves.

Oh, an enslaved god (from the future), driven mad, and rode by a huge intellect devourer, visible through a hole in their head. Maybe with a bio-cybernetic limb. Possibly one a PC follows. Reduced from godhood, but still a power to be reconed with.

Getting a lot of Terminator vibes here, which I love!