The crux comes at the steepest part of the already very steep route and requires extreme fingerstrength and core tension. I guess that's true for most routes at this level of difficulty, but still. The route is around 18 meters long and doesn't have much in terms of rests, so quite continuous in other words. Alex needed five days of work.
The grade means it's a contender for the most difficult route Alex has ever climbed, which says a lot consider how many hard routes he has done in the last couple of years. Not sure how many 9a's and up he has left to do in Frankenjura, but it can't be many.