You reminded me of Gargoyles which is worth mentioning. Creator Greg Weisman quit over Disney planning to ruin it in Season 3. It was probably a good call because they did ruin Season 3.

Weisman had created a detailed story arc that had a couple more centuries to go. He has continued to answer never ending fan questions and reveal details of the story arc for the following 20 years at "Ask Greg" at Station 8 Gargoyles

http://www.s8.org/gargoyles/askgreg/