I was thinking of making a Druid into a BBEG for a little one-shot I will be doing with kids from the community group I used to DM for.

The premise is, this Druid wants turn back time and make the world as it once was - ruled by nature and beasts.  A world where people lived in small hunter gatherer tribes and had a respect for the land each other.

To that end, he is constructing a tower, that will act as a magic collector and conduit, letting him channel all the magic of the world - basically makeing it so this Druid can cast a 12th level wish spell, by using the tower as a conduit, through which he can weild all the magic in the world for a short time.

To build this tower, he will do anything.  It doesn't matter to him how many people die, or how much of nature he destroys because once he has built his tower, he will be able to undo all the damage by turning back time with his wish spell, and so the ends justify the means.

So I am just wondering what all you fellow DMs think about a BBEG like this and of the premises.

Looking forward to your responses.

I don't think it's necessary for the druid to cast higher levels spells. Just make it so the closer you get to the tower, the less effective magic items and spells are.

Class features already make players strong, just build the druid like a high level player. Also give it support like magic items or an army of firbolgs. 

I ran a similar story arc in one of my games; the Druid was scorned because his amore, a Dryad, had vanished and he assumed it was due to deforestation. He decided to seek out artifacts that would grant him powers from Malar so that he could destroy civilization and return the world to a point where they had to rely on nature once again. 

Some thoughts;

Make a theme for the Druid based on an animal, in my case everything was wolf based. Dire wolves, were-wolves, wolf packs, undead skeletal creatures with wolf skulls, etc. This will help give the players cues that they're on the right path if they're running into creatures of that type. I also created a small Circle of Druids, only six Druids including the bbeg. This allowed for mini-boss fights, exposition, giving the players more cues that they were headed the right direction, and gave me the freedom to drop a Druid in wherever the players were if they went a-stray.

Sell the Druid's reason for this act. It is a heinous act that requires the Druid to potentially break vows and go against the "normal" ethos of Druids. Have rumors, hear-say, and local stories crop up that start building on why this Druid is willing to do all this work. If the pieces of the tower require the Druid to "sell their soul" per-se, have the locations tell a story about the sacrifices the Druid had to make. The more you can humanize the Druid, the more the players will start to question whether they should help the Druid return to society, or just destroy him because evil.

I kinda like the idea Wysperra mentioned, magic is weaker near the tower. I also think that there could be "hiccups" with magic the closer the Druid gets to completing his tower. Starting at a small % but gradually increasing, there is a chance of failure, a chance the spell could be weaker, or the spell could be different. Magic Missile becoming Fire instead of Force, Power Word: Kill is weakened to "less than 80hp" instead of 100, Darkness only covers a 5ft radius. These wouldn't be permanent, instead they are just momentary things that remind the players that something is wrong. It lasts a few rounds, a day, but never long enough to make a spell worthless beyond one or two fights. 

Does the Druid have some way to install some kind of ruling to prevent history just repeating itself? The desire to evolve and develop is inherent, even in real life creatures have built structures and used simple tools before humans even came to be. Termites, though basically blind, build structures of a size that to them are what skyscrapers are to us, animals use rocks and sticks to get at food like rocks to open clams. Ants farm aphids. 

If the Druid simply reverses time then their plan is guaranteed to fail: because animals and creatures (especially any humanoids from back then) will continue to evolve and develop just like they did before which eventually became the towns and cities this Druid is wanting to get rid of. 

Quote from Cyb3rM1nd >>

Does the Druid have some way to install some kind of ruling to prevent history just repeating itself? The desire to evolve and develop is inherent, even in real life creatures have built structures and used simple tools before humans even came to be. Termites, though basically blind, build structures of a size that to them are what skyscrapers are to us, animals use rocks and sticks to get at food like rocks to open clams. Ants farm aphids. 

If the Druid simply reverses time then their plan is guaranteed to fail: because animals and creatures (especially any humanoids from back then) will continue to evolve and develop just like they did before which eventually became the towns and cities this Druid is wanting to get rid of. 

You know, I honestly never thought of this. 

Thinking of it now though, I am sort of thinking that he would be locking the world into an endless cycle.  The Druid uses the tower to cast his Wish spell and all the world is reverted to the way it once was.  The world then progresses naturally and develops much the same way as it did before.  Only this time; it can't ever move beyond a certain point, because when it gets to that point, the Druid is there to use the tower and cast his Wish spell, sending the world hurtling backwards through time, to end up as it once was.

Again and again and again, this cycle is repeated.  

It becomes almost like a closed system.  Development and evolution, followed by reversion, followed by development and evolution, followed by reversion; and so on.

I am not sure if I am making any sense, but hopefully you can see what I mean. 

A self-fulfilling prophecy type scenario, predestination, and a time-loop that doesn't have a glaring paradox! Then the party learns of it and has to thwart the plans. The fun part here is that you can create a very simple failure state; the world reverts. Let's say, for arguments sake, the party doesn't stop the Druid, and there isn't a TPK, how would you handle it? Would the party revert to their younger selves and the whole journey starts anew when the druid begins the building of the tower again? Would the players be placed in that past as their normal selves where they could continue their journey in a different way (butterfly effect!)? Would they be shunted to an alternate timeline, string theory/parallel universes? So many ways that could play out, I'm rather thinking of pulling this off now...

Consider what this tower is constructed of, and how it is constructed. He contradicts himself if he is using "modern" technology (from the perspective of your campaign) to accomplish his back to basics goals. You avoid this if the tower is instead a giant tree, mountain, dead gargantuan creature, etc. If you keep the modern tower I suggest considering whether or not he realizes the contradiction on his own, and how he rationalizes it to carry out his work. If he never realizes it on his own, but one of the players do and point this out to him, how will he react?

You also now have a superficial connection to Stephen King's The Dark Tower. You might enjoy looking into that for more inspiration if you haven't already.

Quote from Korbin_Orion >>

Consider what this tower is constructed of, and how it is constructed. He contradicts himself if he is using "modern" technology (from the perspective of your campaign) to accomplish his back to basics goals. You avoid this if the tower is instead a giant tree, mountain, dead gargantuan creature, etc. If you keep the modern tower I suggest considering whether or not he realizes the contradiction on his own, and how he rationalizes it to carry out his work. If he never realizes it on his own, but one of the players do and point this out to him, how will he react?

You also now have a superficial connection to Stephen King's The Dark Tower. You might enjoy looking into that for more inspiration if you haven't already.

The tower has a stone shell, encasing a crystal core.  

The crystal was planted by the Druid and infused with magic energy.  That magic infusion causes the crystal to grow.  It grows down into the earth and up into the sky.  As the crystal grows, it sucks the magic out of the world and stores it, like a giant lacrima (sp).  Also, as it grows bigger, the Druid builds a stone shell around it, to create a stone tower.  He does not do this on his own of course, he has henchmen - those who believe in the same thing or see him as a way of acquiring the power that they desire - these henchmen are like lieutenants that control gangs of creatures from the weaker races, Goblins and Kobolds and so on, (perhaps even some of the stronger but less intelligent races like trolls and so forth) and it is these slaves who mine and sculpt the stones and build the tower.  Though they do so on the orders of the Druid's henchmen, who in turn act on the orders of the Druid.

This tower is built for two reasons.  

1. to protect and contain the crystal
2. to house the Druid and his henchmen

Although the henchmen leave the tower and go out into the world, where the characters can encounter and defeat them one by one, they always return to the tower on a fairly regular basis; and the Druid himself never leaves the tower, so to defeat him, the characters must eventually go there.

Once the crystal has reached a certain size, it will have absorbed a sufficient amount of magical energy to allow the Druid to cast a 12th level spell. At this point, the tower will be complete.  It will also be the only thing standing in the surrounding area, as the crystal will have grown down into the earth and spread out like the branches or roots of a tree, sucking all the magic out of the surrounding earth, causing some species like plants and trees and some animals to die off completely in the affected area, and causing others to morph into twisted ravenous creatures that have an insatiable hunger for magic.

You could think of these creatures as life/magic draining vampires (although not a vampire in the sense of the MM) - they attack any living thing that enters the affected area and attempt to suck the lifeforce/magic out of them, using it to reinforce their ever-dwindling supply.  Some of them have managed to retain a portion of their intelligence and pose a greater danger to the party, while others have just become beasts and lack any kind of intelligence at all, acting purely on the instinct to feed.

Those who have been turned entirely into beasts will just rush and attack anything with a sufficiently high-level level of magic, without any real thought to their safety.  The ones who have maintained a portion of their intelligence can still create rudimentary plans, resisting rushing in and planning basic ambushes and things, or working together to take down something with a high enough level of magic, that all of them can have a bite.

Thus, not only do the characters have to defeat the henchmen to acquire all the information they need to assault the tower itself but in order to assault the tower and ultimately defeat the Druid, they need to make their way across an extremely dangerous barren plane, inhabited by ravenous beasts and life/magic devouring creatures.  Once inside the tower itself, they must then solve a series of puzzles, that will get them to the very top of the tower, where they will have to defeat the Druid by stopping him from casting the final spell.  They don't have to defeat him by killing him, there are lots of ways he could be defeated.  Breaking the crystalline machinery of the tower, persuading him that what he is doing is wrong, taking control of the tower and using its magic to undo what he has done, or any number of other ways.  

Of course, they can still just kill him if they want.  It would not be an easy fight but if they wanted to go that way, then sure, they can kill him.  Of course, that would then leave a tower full of stored magic,  just waiting to be used.  So if you had access to all that stored power, and could cast a 12th level Wish, what would you wish for?

I hope all of this makes sense and that I haven't just rambled on and on for nothing.

Ah, yes. Crystals are integral to all time-traveling machinations.

I like a lot of your ideas. The main thing I'm going to critique is the emotional impact for your players brought on by your BBEG vs his lieutenants. Since your Druid never leaves his tower, your players never interact directly with him. Compare with Ganondorf or Sephiroth. They keep popping up throughout the story, teasing, threatening or hindering us along the way. This role is instead filled by the lieutenants. The minions/"mini-bosses" are naturally going to get more character development and be more memorable to the players than your Druid is. 

This isn't inherently bad. Lord of the Rings had the spirit of Sauron literally bound to his tower. It worked in that Sauron was intended as an enigmatic force, and he still had a direct tie to Frodo through the ring, appearing in dreams, visions, magic soup bowls, etc. Many movies and t.v. shows get around this cause we get to see both sides. We can become attached to the villains through narrative rather than through our heroes directly interacting. 

Here, your Druid has plenty of potential for character development (beyond enigmatic evil force) that only you will ever know of or see. The players will mostly see no more than the results of his schemes, attempting to fight back or prevent them. Consider situations where he would in fact leave his tower. The biggest one to me relates to his intelligence/arrogance. In so many stories, especially video games, you have a situation where the BBEG keeps sending his minions at the heroes.

First the weak minions, but they are weak and get easily defeated. Okay, I'll send somebody a little stronger, but our heroes are also a little stronger, too. Ok, let's send a real threat. Not our biggest threat, but still one tough cookie. Well this minion was more of a challenge, and maybe the heroes had to rethink many of their motivations and strategies, but they still come out on top. The BBEG is literally training the heroes to be his own downfall. Maybe after the third mini-boss is so readily defeated, he realizes that he can't rely on his minions in this particular situation, skips minions 4 through 9 and comes to deal with the adventurers himself. 

Now we are in a situation where you say the Druid doesn't care who he has to kill to accomplish his goals. Compare again to various depictions of Ganondorf, who likely feels the same way. In The Windwaker, he was so arrogant that instead of killing Link directly at the top of his island fortress, he just knocked him off of the balcony and into the ocean where Link luckily survived. Maybe he understood he could survive but didn't care, thinking that by displaying his sheer amount of power was enough to scare him away. In Ocarina of Time, he had many opportunities to kill Link when he was weaker (young and adult), but he was smart enough to deduce that this boy had some connection to the princess, and used him first to enter the sacred realm and secondly to lure Zelda out of hiding.

Do either of these reflect the intelligence and/or arrogance of the Druid, where he may need to get directly involved. Is he smart enough to attempt to kill the party when they are weaker once he realizes the threat they pose, or is he so arrogant that he is just going to keep throwing minions at them and realize too late that they are on his doorstep? Are there any other twists on these concepts you can add to your Druid to introduce him to the party at various points in the story without killing them? Voldemort was smart enough to attempt to kill Harry as a baby, but there were magics greater than he had at his disposal at play, and he still was so arrogant that he didn't seem to consider that he was wrong about Harry and ignored Neville completely. 

Even if you still think he is far more likely to never leave his tower, or at least never interact with the party until the last portion of the campaign, find ways for the party to meet people who personally knew the Druid before his rise to power. Someone who can tell his story as a child and young adult, before he began construction on his tower. Maybe you find magical recordings/memories of events that took place in the past, such as Zelda: Breath of the Wild, the Harry Potter Pensieve/Tom Riddle's diary, and Final Fantasy 10 data spheres. 

Also, hope this eases your concerns of rambling. I do it, too.

This is sounding a lot like the Reapers from the Mass Effect series - I dig it!