self-willed

adjective

1. 1

   Obstinate; strong-minded; unyielding to the desires, concern or opinions of others.

   “He was so self-willed that he refused to do anything that did not grant instant satisfaction or direction.”

2. 2

   Possessing self-will; determined to pursue one's own desires or adhere to one's own opinion..

   “The idea of self-willed machines, which could decide to take over the world, scares all the people smart enough to create such devices.”