Just a quick note, when you spend a Hero Point to re-roll, you only get he +10 if you rolled a 10 or below, so that you always get at least a 11-20 on your re-roll. As Wolverine rolled an 18, he does not get the +10, but a 28 is still high enough ;)
I re-read Master Plan (M&M 2nd ed, pg. 62)...