Hi DMs! I’ve been running a home brew campaign for about 2 years now with a group of 4 players. They are currently level 9. The BBEG is a self-proclaimed god called Dues Novus (or as the players call him, ****** Mopus). His mission is to expose the real gods, reduce them to nothing, steal their followers, world domination ensues. Most of the PCs are religious which adds some great conflict. Dues Novus is able to mind control living beings via a crystalline disease called Besiddelsite. The players have found a cure to this disease though it takes a few rare items and a ritual.

Dues Novus has talked to the PCs through possessed NPCs and dreams, never actually showing up himself. He’s offered for the players to join him, showed them what he was capable of. The players turned him down and are determined to rescue their respective gods. 

Basically, I’ve been building tension for the past few sessions and everyone’s aware we’re approaching the BBEG fight. The one thing I’ve failed to plan is how the BBEG fight is going to initiate, and it feels wrong to just throw the boss at them. The players don’t know where to go from here, where to find Dues Novus, and neither do I. Any ideas would be very much appreciated! 

Classic villain. That dude definitely has lieutenants, people who were of more use to him afraid or persuaded than controlled directly. Being the intelligent villain he seems to think he is, he won't send just one combat-ready lieutenant -- he'll send all of them at once.

Perhaps by some source, the heroes are aware that Dues is sending everything he has to destroy them. But he is stuck doing... something, I don't know the plot well enough to know, at his Evil Temple of Doom (trademark). Have an ally of the party point out that if they can get by the lieutenants, Dues Novus is wide open for attack. If the party follows this plan, they need to get past the lieutenants. Ask how. They'll figure out the rest for you.

After they bypass the lieutenants' coup d'état, the party arrives at the Evil Temple of Doom (trademark). Now, either the heroes need to infiltrate the temple, fight their way in, or dimension door straight to the final boss if you're feeling generous and they've already seen the place where he is.

As for how they know where the Evil Temple of Doom (trademark) is, that's easy. As Dues begins a... thing... to cast down the gods from their thrones, the party's Clerics, Paladins, and assorted Warlocks receive a vision from their respective gods, all with the same message: "This guy is shining a laser pointer into our eyes, can you come turn it off? Here's his coordinates."

The rest is up to yoooouuuuu!!!!

Part of the problem of having a BBEG is that issue of how do I get the party and BBEG to fight. 

In previous campaigns I've literally had parties reject the BBEG storyline altogether so had the enemy pursue the party which leads to that surprise encounter with a big boss. Since then I've actually run a more layered and more detailed world where villains aren't so much Big, Bad or Evil, but more normal people with normal motivations that run counter to the party belief systems. 

Given that this BBEG seems to be going after the realm of the divine if your world requires clerics and paladins to be associated with a god I'd suggest hinting at divine magics becoming weaker due to the damage this guy is going to the gods. Make your clerics and paladins roll any spellcasting at disadvantage until they take on the BBEG. This should encourage and motivate the party to address this very real threat. When facing the BBEG you could even explain that the Paladins and Clerics feel infused with the last drops of power the gods are able to bestow in order to help them through the fight. I assume they already know how or where this guy might lurk given that they've met him previously. If that's not the case a simple vision to one of the party from their respective gods should do the trick. Make it a bit vague so the party have to piece some clues together (and thus feel like heroes for solving it), but a vision solves the issue of getting from there to here.

Going back to the idea of lieutenants and a temple, perhaps this self proclaimed god (if he uses undead) has bestowed his lieutenants with divine magic to raise fallen soldiers and sends forces into towns and cities in his name, and the only real way to stop the lieutenants' forces are to cut off their divine connection. Im not sure if your BBEG employs the dead in his forces, as this idea wouldn't work otherwise.

Quote from InheritanceTheTeifling >>

 

Basically, I’ve been building tension for the past few sessions and everyone’s aware we’re approaching the BBEG fight. The one thing I’ve failed to plan is how the BBEG fight is going to initiate, and it feels wrong to just throw the boss at them. The players don’t know where to go from here, where to find Dues Novus, and neither do I. Any ideas would be very much appreciated!  

Depending on what level you plan on doing this and go for the traditional War in Heaven.

The gods have called upon their faithful - which includes the party (and many others) to battle on the Plane of the Gods.

The party will fight numerous beings that follow this Dues Novus - and eventually, storm the temple in the Heavens of Dues Novus - with tons of other NPCs (just there as flavor to scale the size of the war). While making their way through the temple - you got more monsters, traps, etc., but it's the actual party who locates his chamber and the battle begins.