Weapon Group Adaptation (Combat)
Benefit(s): Choose a weapon group (excluding siege weapons and siege firearms). That weapon group is considered associated with disciplines you have access to. Note that this does not change the initiation requirements of maneuvers from those disciplines (for example, a warlord who takes this feat might have heavy blades associated with Solar Wind, but still cannot make a ranged attack with them without further feats or abilities that allow him to use a heavy blade as a ranged weapon).
Why im considering it, I plan on joining the Black Thorn Knights for access to Black Seraph discipline, I plan on using the ranged touch attack abilities from that discipline in my arsenal of moves, however I normally use a cestus/unarmed strikes for my main weapon. Is it worth it to spend a feat to make unarmed strikes a discipline weapon for Black Seraph?
Weapon Group Adaptation is really only necessary if you plan on using a lot of saving throw-provoking maneuvers. Now, 2 of the 4 ranged touch strikes do have saving throws, but only for fear effects, which is very tenuous to build on. With that in mind, unless you have some other effect beyond the base +2 DC, I wouldn't (with your build). It's still a good feat, but not really worth taking to provide a little extra edge on what seems to be an ace in the hole.
i guess you have a point, i've to take advanced study instead.