Board Thread:General Discussion/@comment-99.231.209.195-20140315204737/@comment-132.159.205.15-20140417133456

even Marie who was on death's door with cancer was able to match a Reaper for a bit.

My guess is that the longer a grimm deals with wessen and trains the more powerful they become as Nick has only gotten more stronger and more agile as his dealings with the wessen have gone on. This would even explain why the reapers hunt all grimms so intently, as the older they become the more powerful they become and thus the harder it becomes to kill one. One could also reason that since neither the wessen or the grimms themselves have ever study the Grimm power that no grimm truly knows what he is capable of, and only time and experience yields to them their full physical prowess. I find it amazingly funny that in all the Grimm diaries and all the grimm legends that no one has ever studied or traced the origin of the grimms. Its obvious that they are more powerful than we are lead to believe based on how even the primordial Wessen were afraid of them, and the primordials are even stronger than the standard wessen.