So I played my first game of AoT and enjoyed it a lot. I did have one question that I THINK I found the answer for in the rules, but I wanted to be sure.

I believe it's phase 3, where the titan gets to activate his powers based on titan faces rolled by the players. I guess my question is 2-fold:

Do the players get back ONLY the dice that were USED by the titan to resolve a power? (rulebook says to "return the used dice", which makes me think the answer is yes)

If the answer is yes, is using dice for powers compulsory or could I choose not to use ANY powers to prevent the corp members from rerolling them?