The Phoenix V12, Niagara Glen
The Phoenix was a project of mine since 2012 and I'd put in at least 7 sessions on it. It never ever felt any easier and in the end I just had to practice over and over and beat it into submission. The holds are often wet and the pinches drain me. Personally this may be the hardest climb I've ever done.
At the end of the video I also include some additional "BONUS FOOTAGE" of a fall so check it out if you want.
The Phoenix V12