Superstring style time travel, like sliders but also through time. Sliders.
Billy Mays will sell us his big city slider station.
The parallel time line method is the most intellectually lazy way of preventing paradoxes.
As I elluded to in this or some other time travel thread; the better and more compelling solution is having only one controller of time travel who does so with both omniscience and intention. Nozdormu's split personality rules out this possibility unless Aman'Thul is aware of everything he will do and has the ability to revoke his power across all time, including when and where he goes bad.