Dastari (who's full name has enough letters for two alphabets) worked on Space Station Chimera on developing time travel by recreating the Kartz-Reimer experiments. He had used technological augmentation to make the Androgum, Chessene of the Franzine Grig into a genius.
With Chessene, a prototype time machine an un-altered Androgum, Shockeye of the Quawncing Grig, Dastari abducted the Doctor from the space station and, having landed in the city of Seville on the planet Earth, worked with to find the secret of the Rassilon Imprimatur for the Sontaran Stike. He later supervised the partial genetic transformation of the Doctor into an Androgum.
Dastari walked on in his partner, Chessene, as she lapped up the blood of another incarnation of the Doctor who had come to rescue his past self. When the disgusted Dastari stated that he now considered Chessene now animalistic as ever, she turned on and killed him. (DW: The Two Doctors)