I don't remember the regeneration limit every actually being set in stone, except in the old Doctor Who RPG. The only place I remember it being mentioned was that the Master had "used up his regenerations" and was forced into a vampiric existence to stay alive. This was after Roger Delgado had died in a car accident and before they had cast Anthony Ainley as his successor, so they had Peter Pratt or Geoffrey Beevers running around in rather gruesome makeup, looking like something out of a Hammer horror film.
Ebony the Black Dragon
http://ebony14.livejournal.com
"Good night, and may the Good Lord take a Viking to you."
Ebony the Black Dragon
http://ebony14.livejournal.com
"Good night, and may the Good Lord take a Viking to you."