So I have seach for how monastic legacy works with classes that stack with monk for the purposes of unarmed strike damage. I haven't really found much info that helps. So I really wish they would come out with an FAQ on the matter, unless I have missed it.
So as we all know monastic legacy reads:
Prerequisites: Still mind class feature, Improved Unarmed Strike.
Benefit: Add half the levels you have in classes other than monk to your monk level to determine your effective monk level for your base unarmed strike damage. This feat does not make levels in classes other than monk count toward any other monk class features.
Now I will be using the Brother of the Seal abilities and it reads:
Unarmed Combat (Ex): A Brother of the Seal’s class levels stack with any monk levels for the purposes of determining his flurry of blows, stunning fist, and unarmed strike class features (including determining damage dealt by his unarmed strike attacks).
Now I read monastic legacy as half the levels other than monk, which brother of the seal is not a monk. Even though BotS says its levels stack with monk levels, it doesn't say that it is a monk. Also I believe that these stack because I don't retain any other monk levels so therefore I am considered a class other than monk. I just want opinions/anywhere it shows this does or doesn't stack officially.
Amusingly I think it works as written. Probobly not intended, but it works. That being said, you are getting 1 size category per 8 non-monk levels (between +1 and +2 damage) increase for that feat, so hardly broken. You would need to have 16 non-monk levels to make Monastic Legacy better than Improved Natural Attack, and Imp. Natural Attack is not even that great.
So at level 19 (monk 3, other 16), you could have this one feat give you +4 damage. Pretty cool, but the sky won't fall.