I decided to give a try to the snowflake method. The idea is that you gradually expand the story from a blurb into a full draft. This question stems from the character-characterization step, but it applies in general to the understanding of a character.
I am at the point in which I need to clarify an abstract goal and a concrete goal for each character. My issue is that I first came up with the plot, and then fleshed out characters to fit their purpose. Now I have a character whose abstract goal should be
vengeance
and their concrete goal is
exacting revenge against the (yet to be found) perpetrators of (a certain action)
I have the impression that this is not quite correct. It feels too monolithic and one-sided to have any chances to succeed as an interesting character.
To give a parallel, if you are familiar with Hamlet, from the plot I would have characterised the abstract and concrete goals for the MC as 'avenging his father' and 'punishing the uncle' respectively. On the other hand, perhaps I am completely missing the point and the abstract goal should be along the lines of 'Setting a role model for Denmark, as befitting of a future king'.
The question is: how to flesh out the abstract goal for a character when the plot is formed but the characters still need to be fully crafted?
A related snowflake question, for those who are not familiar with the approach.