This is long, but involves the murder of entire families, so if you're into that kind of thing, read on...
One of my human civs was on an island. After initially deciding to ignore them completely, I finally decided to spawn as a citizen and wreak as much havoc as possible from the minute I was "born." First I went to the civ's only fortress, where I found nine or ten peasants in addition to the lord and lady consort. A quick interrogation to find out their family histories led me to discover that the peasants were all distant members of the lord's family. (I suppose this is probably normal.)
I retired and went to Legends Mode to examine more closely the fortress family tree. Here I learned the horrible truth - the lord, Rere, was the youngest grandson of the previous lord. He was forcing his aunts, uncles, and cousins - the rightful heirs - to live as peasants while he ruled the fortress. This would not stand.
Upon returning to adventure mode, I decided to kill the "wrong heirs" and let the right ones live, even if it meant my death. First I killed the lady consort and set about crippling Lord Rere ever so slowly. I sliced off both his feet and left him a bleeding, vomiting mess, but by now his uncles were coming after me, and I was pretending to do this for them. In order to escape, I cut off at least one arm of just about everyone...and in an unfortunate counterstrike, I stabbed poor Uncle Otur in the brain. Fortunately he was the childless one. Aunt Pibang and Uncle Palath were relatively safe. Their daughter, young Milo, whom I had decided was the true heir, was untouched.
Dodging people I didn't want to kill took its toll, however. I killed Uncle Ebe to save myself, but after hopping back into an earlier room I was somehow sliced in the skull by Lord Rere himself, and his chromite slicing knife meant the end of me.
However, by killing me, Lord Rere made himself an enemy of my hometown. When next I spawned in that city I brought with me Kisnast and Corud, a hammer(wo)man and spearman, and went after the fortress again. Lord Rere attacked me unprovoked. This act was looked upon as a betrayal by his aunt Pibang, mother of the rightful heir. She herself killed her nephew.
Chaos ensued. My hammerwoman, Kisnast, killed Pibang in retaliation, and in the scuffle somehow decided she was my enemy, as well. My spearman continued to be my companion, and he attacked the hammerwoman. Uncle Palath, Pibang's widower, somehow managed to die in the struggle. I chopped off Kisnast's hammer arm, and Corud brought home his spear.
I went downstairs, where I saw the child Milo, the only survivor. Somehow, by saving the murders for my companions, I had managed to remain acceptable in her eyes. I spoke to her and was able to report the good news - her traitorous uncle Rere was dead. She congratulated me, and sounded happy...perhaps she didn't realize that her parents were also dead. Along with two uncles. And her cousin-in-law. I retired, presumably to act as her regent.
All was well in Fortress Packclocks. I went back to Legends Mode to admire my handiwork - most of a noble family, all brought down in the year 551. Then I looked at my former companions' pages...where I learned that Kisnast, the hammerwoman, had been the last surviving daughter of Corud, the spearman who had killed her. Magnificent.