Bad / Crazy
lunacy - Stupid or crazy ideas or behavior that is likely to have bad results
When Edwin Hubble suggested in 1922 that most of the little dots in the sky are entire galaxies, most scientists thought that the idea was sheer lunacy.
megalomaniac - Someone who has an unnaturally strong wish for power and control.
The dictator showed signs of being a megalomaniac even as a child, the way he bossed everyone around in the schoolyard.