Well, the ancestor of a troll is said to be the only other troll with a genetic match closest to them. Ancestor and descendent are said to have their fates tied closely together. The descendent is to look for clues to learn the identity of their ancestor, and in turn, the ancestor is to influence their life somehow even when deceased.

For example, they may guide them in ways, or the descendent will finish the business of the ancestor such as in cases of revenge. For others, it is righting the wrongs the ancestor did. Sometimes, it may not always be obvious, but the descendent may still find themselves going down the path of the ancestor even before they learn of them.

Highbloods tend to put more stock in it then lowbloods.