When my new Blackbelt was in the tank he came from he was kicking the crap out of all the other fish. He nearly killed an Oscar that was way bigger than him.
I came home last night and my new BB was getting his axx kicked, and was all beat up looking. After keeping an eye on my tank, he was constantly being harassed by my Vieja syn that is at least 2" smaller than him and my Texas. This morning he is just staying at the top of the tank not looking to good. Hopefully my other fish will adjust to him being in the tank and leave him alone.