Who is the strongest character

[image source] (https://www.google.com.ng/amp/s/winteriscoming.net/2017/07/10/official-images-game-thrones-season-7/amp/)

This movie is highly cool. Have seen movie that lost its audience even at just season 2 but this movie has stand out among all else.

Every season leaves it's audience with thirst for the next.
If you have seen the movie,
1– Who is your favorite?
2– Who is the naive one?
3–the weakest?
4–the strongest?
5–the over ambitious?