I would instead say the one in danger of disrupting the dojo is the one who's attitude makes everyone avoid him. He obviously isn't correcting his behavior, and others should not have to train with him if he is misbehaving.
I would not make a scene during class, however. Just don't sit near him, and make sure you get a different partner before he can choose you. He should get the hint if everyone avoids him. If not, since your speaking to your sempai didn't get any results, you could discuss it with your sensei--- but off the mat would be my suggestion. He will decide what, if anything, he will do about the situation. Most senseis, however, should have noticed by now that one student is being actively avoided by the rest, and I would think has asked a senior to do something about it (as in, have a talk with Mr. Muscles).
Training with all sorts of partners is important, but this one refused to work with his partner in the way requested, and then belittled his partner. What he needs is a larger, stronger senior to imobilize him a few times (or better still, a SMALLER partner to imobilize him a few times) to give him a feel of what kind of partner he is being.
Personally, I dislike training with someone who is so negative, tolerate such behavior a max of 8 times, and if they still refuse to help me with what I ask of them, then I shut them down the next time they try to do the technique. Since I am usually half their size, it solves the problem as they either straighten up, or they avoid me the rest of the night. It takes very little to prevent your partner doing the technique shown, just a refusal to give an attack with the right energy for the called for technique.No one learns anything when all you do is shut each other down.