Hilsee

Hilsee was a colonist on the planet Isos II.

When the Cybermen invaded the colony, Hilsee was captured and converted into a Cyberman. However, the conversion process went wrong and Hilsee escaped. Five years after the invasion, he hid Zoe Heriot from the Cybermen.

Hilsee later sacrificed himself to prevent the Cybermen from invading Earth. (AUDIO: The Isos Network)