@AKS: Look at this
The story above is the Alaskan/Canadian equivalent of Kullervo. In fact, one version I found here

begins: "A boy and his sister during a seal hunt on the sea ice were cut off from people. No-one could help them as their ice pan drifted away. Their parents and older brother gave them up for dead. But this was not so- after many days the wind blew the ice pan near the shore of a strange land where people lived. Each was adopted by a different family and this is how they came to live among strangers."

In fact, after Kaujjarjuk got his supernatural strength and killed the people who abused him, I thought his sister lived in a separate village or something and he was going to wander across the tundra, meet a girl on the way to finding his sister, marry her and then find out she was his sister and then they'd both commit suicide.

That idea is horrifying. All the more because some people probably still do it today.