The only competition I can think of is Caligula. The really sad part is that O. seems to be giving his base exactly what it wants. That's a recipe for disaster.
He’s getting really close to Caligula.. only difference is, he will avoid, or outright deny (and/or redirect blame (personal or otherwise))..
AND, I personally don’t think he has IQ above 80 (being generous).. he is a puppet being guided by puppet-masters.
It was Nero who fiddled (or played the cithara) while Rome burned. Some say he started the fire and put the blame on the Christians, who he had executed. Even though it is not certain what Nero did while Rome burned to the ground, we do know what Zer0 is doing. Zer0.