Time Manipulator

A Time Manipulator, as described by, was a cerebral mass (the size of a planet) capable of dominating and controlling time anywhere in the cosmos. (PROSE: Time and the Rani) Operating on a grand scale, it was able to change the order of creation.

The Rani planned to use the Time Manipulator to change the history of any planet in the belief she should intervene in the evolution of various species.

Construction
The Time Manipulator was the conjugation of time particles and brain cells. To accomplish this, 's plot involved collecting the intellects of several geniuses from across time and space (including the Doctor's knowledge of time) and distilling them into a giant "time brain" on the planet Lakertya. The Brain would create/find/synthesise a lightweight substitute for strange matter, which it eventually did in the form of loyhargil, to detonate the strange matter asteroid passing Lakertya, since the only substance that could explode strange matter was strange matter. The loyhargil would be loaded onto a rocket with a fixed trajectory matching the solstice of the asteroid and fired at it.

The strange matter explosion would re-enact the Leptonic Era that followed Event One and produce helium 2, which would fuse with the upper zones of the Lakertyan atmosphere to form a shell of chronons. In the same millisecond the shell is formed, the hothouse effect of the gamma rays would cause the primate cortex - the segment of the brain responsible for thought - to go into chain reaction, multiplying until the gap between shell and planet was filled, essentially creating a planet-sized brain. The Rani would then return in her TARDIS after the turmoil had subsided and take control.

History
The Rani attempted to transform Lakertya into a Time Manipulator, feeling it wouldn't be necessary if the Time Lords hadn't refused the intervene in the evolution of other species. With this "monstrosity," as the Doctor called it, the Rani would be able to redirect evolution wherever she felt it had taken the wrong route. She planned to return to Earth in the Cretaceous Age, feeling the potential of the dinosaurs was never fully exploited.

The Doctor was able to delay the countdown of the launch, causing the missile to miss the asteroid. In the process, the Brain was destroyed, preventing the Time Manipulator from existing.(TV: Time and the Rani/PROSE: Time and the Rani)

Similar technology
Jodafra called the Windigo a "Time Manipulator" as it's screams could paralyse time-fields, essentially freezing individuals between seconds. (COMIC: Bad Blood)

Before evolving into their current plane, the Chronovores' ancestors built the Darkheart, a space/time conduit that could transmit energy to any point in time and space. Unlike a TARDIS, the Darkheart had direct access to time. Whereas history could not be changed without creating an alternate timeline, this was only true when travelling in a TARDIS as the Darkheart actually reshaped the universal matrix to account for changes that were made. (PROSE: The Dark Path)