Skagra

Doctor Skagra; the Geneticist, Astro-engineer, Cyberneticist, Neurostructuralist, and Moral Theologian was a native of the planet Dronid.

Think Tank and designs on the Universe
At some point he departed Dronid and set up Think Tank with the aims of creating the sphere.

Following the creation of the Sphere he set out to search for Shada and Salayavin (he most likely found out about Salyavin from one of the Time Lords on Dronid).

Skagra wanted to 'possess' the universe, and for this he needed Salayvin's ability.

Skagra travelled to the planet Earth in order to find Salyavin, whilst there he obtained a copy of Professor Chronotis' mind and The Worshipful and Ancient Law of Gallifrey; the key to Shada the Time Lord's prison planet.

Skagra was left trapped within his sentient ship following the Doctor's alterations to it.