One of my starting seven became king about three months in. A migrant wave came right after, and we dug out four 10x10 rooms for him. We smoothed and inexpertly engraved the walls and got a lucky break with a legendary blacksmith mood (built an iron weapon rack). First crisis averted!
More migrants came, then a vile force of darkness! The attackers were dwarves, though... I waited a bit for the end to come, but they instead walked across the map from the top to the right side and left. Second crisis averted!
A bit later, more migrants, then a treacherous goblin ambush! My quickly press-ganged militia killed all but one of them (thank Armok for six armed hunters). The last one, a lasher, killed a dozen dwarves before the rest overwhelmed him and beat him unconscious. And then kept hitting him. He had an +iron helmet+, and they kept punching him there, to little effect. Every once in a while, a dwarf would wrestle him and break an arm or a leg. 53 pages of logs later, he had his shoulders, upper arms, lower arms, upper legs, lower legs, and most of his fingers broken, but he was still alive. My military was getting thirsty by now, and the lasher was bleeding a bit, so I figured I'd just let him bleed out. I cancelled my orders and watched the militia disperse...
Then he got back up.
He crawled to my fort entrance, bit a cat on the head, and shook it until it died. Then he did the same to a thresher. I went to order my military to attack again, and the game crashed. I'm pretty sure he was going to end me, though.