No idea about the comment on Improved Knight's Blade...Text of Improved Knight's Blade does not match table. And there are issues with granting an enhancement bonus based on class level - better to make it something that scales by HD, or just let you enchant yourself as a magic weapon a la the Ancestral Relic feat and have the effect extend to anything you wield.
As for the scaling thing... Maybe start it out low, and scale with IL, or something? Cap it at half class level, of course.
Yeah, but the Bloodstorm specifies that it stacks with the Warblade one...Weapon Aptitude is primarily a warblade ability.
Guess I could change it.
Maybe the UMD thing will be changed to "you are able to weild any weapon with a special requirement, such as being only usable by elves, or being only usable by clerics, as though you met that requirement.". Does that read better?Seems odd that it doesn't have Use Magic Device as a class skill or prereq; the capstone is also pretty meh, being essentially "your weapon gains a +1-equivalent enhancement, and you can use swords that harm an alignment your enemies don't have". You could just grant a bonus on UMD checks equal to your class level.
As for the meh part...
It says "specific weapon". Weapons of Legacy grant you feats for each specific one.
Also, isn't the main reason to dip Master of Masks access to all weapons? Because you get proficiency with ALL weapons as well.