There are plenty of crazy Rulers, but the three that stand out for me are Caligula, Kim Jong-LI and Vlad the Impaler. If you want to know what any of these people look like, or just want to see Kim in that sexy tracksuit, I've included pictures:
Kim is the pretty batshit by crazy standards, and in case the whole importation of Swedish whores and injecting of virgin blood didn't convince you of this, then don't worry, as Kim never stops with the crazy.
To start with, Kim's solution for the famine plaguing his country in 2006 was to breed giant rabbits. That's right. Giant. Fucking. Rabbits. I don't know if he intended for his nation to eat the rabbits, or if he was going to train them to lay siege to KFC. All I know is Giant. Fucking. Rabbits.
Secondly, all North Korean children are taught that Kim never has to take a dump. Ever. And also, when he was born, rainbows appeared out of nowhere.
Kim absolutely hates his height, and hates others of similar dwarfism, so naturally, as a whack-ass midget, he had to do something about this problem. What he did was send out a pamphlet to one of his cities describing a new "wonder drug" that could make short people taller, but really all he was trying to do was group up all the shorties that responded to his pamphlet to be "sent off to a number of uninhabited islands in an attempt to combat this substandard gene". Luckily, all the short people found out before they all got shipped off, but I suppose it would have been kind of cool if we had a midget version of Lost.
This is where all vampire myths and stories started, and it's easy to see why with that groovy moustache. There were plenty of rulers who executed their enemies by impaling them, but Vlad took this to a new level by developing his own technique, which consisted of him: lubing up the stake with pig fat or oil first, making sure the object they were being impaled with wasn't too sharp so as they would writhe in agony for hours or even days, and then ramming it up the victim's anus or vagina before putting the impaling object upright so they would be impaled by their own weight. Oh, and his second favourite method of killing and torturing his foes (and innocent peasants of course) was chopping off their sexual organs. But the worst part is that he enjoyed watching his men do this.
The most famous massacre associated with Vlad that doesn't involve impaling was when he invited all the poor people around to his home for a feast. After they had all finished eating and drinking, he set the place on fire, killing them all. He's just lucky Vlad the Arsonist doesn't have the same ring to it.
Kim may have convinced a whole generation of children that he never needs to take a crap, and Vlad may have used his stake/dildo combination to impale an innumerable amount of people, but Caligula just didn't seem to understand. There's being a heartless bastard, and there's being clinically insane.
Caligula had a relationship with his sister Drusilla's husband Marcus Lepidus, which is fine and all once you get past the adultery, but then he forced Drusilla, the man he was having an affair with's wife and his sister, to marry him. And that's not even the worst part. After marrying her, he got her pregnant, and he began to get impatient to see what the baby would look like, so he disembowelled Drusilla and took the phoetus from her womb. The next year, he had Marcus Lepidus killed.
There were also many other similar relationships, such as stealing his friend's wife-to-be at the wedding, committing incest with several of his sisters and since he gave his horse a tonne of jewellery, built it statues and generally treated it like a God I think he had a bestiality thing going on too. The only excuse for this is that Caligula's mother drank large amounts of moonshine whilst she was pregnant.