Lord Zardoz
Explorer
I am not very big on story intensive D&D games myself, but I do have one suggestion.
Rather than engineer that specific ending, present it as a player choice. Save the world or save themselves.
On door number one, the players can choose to save the world by some mechanism that would cause them to die. Players are dead but all the other people on the world get to live.
But with door number two, the players can get the hell out of dodge. They can turn their back on the world and let everyone die, but they manage to escape to another plane of existence. Or they get to become gods of a new world. Or whatever else sounds suitably appealing.
If you frame the choice correctly, it becomes 'do the right thing or be class A dickheads'.
D&D should fundamentally be about the players being able to choose what happens. When you turn players into spectators for attempt at creating a Lord of the Rings style epic, they usually do not have as much fun.
END COMMUNICATION
Rather than engineer that specific ending, present it as a player choice. Save the world or save themselves.
On door number one, the players can choose to save the world by some mechanism that would cause them to die. Players are dead but all the other people on the world get to live.
But with door number two, the players can get the hell out of dodge. They can turn their back on the world and let everyone die, but they manage to escape to another plane of existence. Or they get to become gods of a new world. Or whatever else sounds suitably appealing.
If you frame the choice correctly, it becomes 'do the right thing or be class A dickheads'.
D&D should fundamentally be about the players being able to choose what happens. When you turn players into spectators for attempt at creating a Lord of the Rings style epic, they usually do not have as much fun.
END COMMUNICATION