Quote Originally Posted by Heliomance View Post
I'm fairly sure that there's a line in CW that says that if you cease to meet the prereqs for a PrC, you cease to gain its abilities. So once you've retrained your weapon focus back to katana, you don't get the abilities from Master Thrower anymore.
Once you get into Bloodstorm Blade, the katana (and anything else you can get your hands on) becomes a thrown weapon. So that's not really a problem.