I'm currently writing a Dungeons and Dragons campaign in which the adventurers will have to defeat a Kraken that is bent on destroying civilization as we know it. However, simply destroying cities with its gargantuan tentacles is inadequate for this Kraken, so it is resorting to building a super weapon to help achieve its goal.
- The Kraken is mostly pulled from D&D lore, meaning titanic tentacle monster with the ability to control the weather and summon lightning.
- It is also extremely smart, and able to engineer complex designs. However, due to its gargantuan size it can not build any intricate machinery itself.
- The weapon must be capable of delivering some form of devastation across hundreds of kilometers. It doesn't actually have to destroy the entire world, but it should certainly decimate a sizable chunk of it.
- The exact size, shape, and style of the weapon can vary, so it could be quite a looming structure. However, it does need to fit into the Kraken's undersea lair. The plan is to raise the weapon up to the surface when its world-ending time.
- While the weapon could be constructed out of fairly complex materials, all resources must be procurable by the Kraken or its many minions over a time period of no more than a few years. For the most part, only oceanic materials are available, although it is possible for the Kraken to sink cargo ships containing other supplies.
- As far as actually building the weapon is concerned, the Kraken will have the help of its minions, many of which are humanoid. These minions are only capable of carrying out simple tasks.
Use of magic:
- This weapon will most certainly use powerful magic to function, however it should be largely based on plausible physics, and theoretically possible in the real world. I don't want to simply have a spell or ritual. Apart from that, the effects of the weapon can be pretty much anything, as long as it brings devastation to the surrounding land. The only condition is that the weapon cannot destroy itself or the area where it is activated.
How shall the Kraken bring about the destruction of civilization?
Bonus points for coming up with a way for the adventurers to ultimately destroy the weapon.
I'm specifically looking for a plausible weapon that the Kraken could create with obtainable materials. Since my campaign has an ocean setting, all materials should be available there. Also, while the Kraken's minions can do a lot of work, the primary components of the weapon should be capable of being manipulated by the Kraken itself, meaning they cannot be too intricate. In addition, the weapon needs to have a large area of affect without destroying the weapon itself, so a simple bomb would not work. Basically, the reason this can't just be any weapon of mass destruction is because I want something that would be logical for a Kraken to create, with an effect that is related to the Kraken's abilities but not something that it could do on its own.
I hope that this extra detail is enough to get my question reopened.