Quote Originally Posted by Elricaltovilla View Post
A: Counters can be used when the die is rolled but before the results are revealed. It has to be this way because you can't counter a natural 20, they're still automatic hits.
That is really wonky... So it's basically an opposed check that automatically fails on a 20. Why didn't you just use the Wall of Blades text instead? It doesn't work against Nat 20's because it is replacing your AC with your Attack Roll. This says nothing about failing against Nat 20's, just that if you beat the attack roll you automatically negate the attack.

The question you quoted my answer from boils down to "Can I use a maneuver I don't meet the prerequisites for to meet the prerequisites to take a maneuver I don't meet the prerequisites for in order to meet the prerequisites to take the first maneuver I don't meet the prerequisites for?" The answer to that is no. But once you meet the prerequisite "one maneuver known of X Discipline" you qualify to keep that maneuver, even if it's the only maneuver you know from that discipline.
I know, I was just mentioning that you can, infact, know maneuvers with requirements that are basically meeting themselves, since you can swap lower level maneuvers for higher level ones and still meet all the known maneuver requirements.