Relia-robot

The REAL best kind of DOOMSDAY DEVICE is whatever's in your heart. If you plan on ending the world, you should end it with STYLE. I came up with my first doomsday device when I was a teenager -- turns out it's theoretically really easy to completely destroy the environment with just a few million dollars of funding, as long as you know where to put it. I'm glad I didn't go down that route, though, as 1) it lacked panache and 2) there was no poetry to it! No being driven mad by grief, no karmic justice, no overblown quest for revenge, no nothing. You never wanna be beholden to your first doomsday plan. Take a few years, mull on it, obsess over it, and you'll come up with something that's both emotionally satisfying AND population-devastating.