In the near future I will be running a campaign where the plot, very roughly goes as follows:
It's the year X. The world has been destroyed in a process that has taken a long time. Most people alive were born during the time when the world was already in the process of destruction. Currently there is only one little part left, and as a last resort the ruler sends the last squad of his/her personal guard back in time to stop all of this before it even happens (any and all time travel/continuity concerns are waved off with a "what are you gonna do, make it worse?"). The timetravel process involves a machine, and they get sent back to the point where the machine was first switched on, in new bodies so while they are experienced warriors they will start at level 1. This is heavily borrowed from the MMO Rift.
So they end up in the year (X-300) or so and have to find out not only how the whole apocalypse, but also stop it in its tracks. It's important, to me, that it's a century or two removed from the start of the plot, because I want to make sure the world is 'new' to the characters and there's no resources available that they know. The 300 is a random number here, but it's the bare minimum. Something along the lines of 500 or 600 years would be acceptable as well. The setting relies heavily on a kind of magic-tech, which is how they're even able to create a timetravel device. In X-whatever the technology would be limited to a more generic steampunk-era type setting.
The intricacies of the time travel, while they are interesting, I will figure out as I go. My current question is how I can succesfully set up a villain whose plan only succeeds 300 years in the future.
Would the actual villain even be alive yet?
What kind of person has that sort of scope to their plans, and if they can rip the world apart 300 years in the future, why not do it now?
If he can ONLY do it 300 years in the future, what sort of thing can the PCs do in X-300 to screw his plans over?
Of course I won't let them end up in the past, 200 years before anything even starts to happen, but still. I have some very vague proto-ideas floating around, but I would like some input on the antagonist's motivations. I never really 'get' why villains want to destroy the world, apart from being batshit, so I was thinking in the direction of "he was trying to do something else bad and he screwed up" or something.