Could someone tell me how Greatjon Umber is used? It says during a challenge he can by kneeled to act like Defender or attacker however wouldn't I have to kneel him anyway to use him? I don't get it and I know it must be simple.

Challenges work like this:

A) Attacking player calls the type of attack, who the defender is, and kneels attacking characters

--> Players take turns triggering effects

B) Attacker assigns stealth, defender kneels defending characters

--> Players take turns triggering effects

C) Resolve challenges

Normally, attackers can only be knelt in A and defenders can only be knelt in B. Greatjon can use his effect in the spaces between to become an attacker or defender, instead of having to be knelt in A or B. So as an attacker, you can wait to see what defenders are declared in B before commuting him to the challenge (assuming some character was knelt in A; otherwise there would be no challenge). As a defender, you can use him between A and B to avoid stealth, or between B and C to see whether the attacker will use events that pump an attackers STR or something similar.

Effectively, Greatjon lets you get around the normal timing of declaring him as an attacker or defender so that you can have more information about whether you need him for that challenge, or can leave him standing and available for a different one.

Perfect Thank you for the indepth answer.

Just to clarify are you saying that when attacking you must commit whoever you want to attack the

re and then? Likewise with defenders? It can't go back and forth between players?

Correct. You get one chance to declare all the attackers you want. Then the defender gets one chance to declare all the defenders they want. You can't add, subtract, change your mind, etc.