In this glitch, Drahmin fights using his normal arm rather than his clubbed arm.
You have to either choose Raiden and verse Drahmin, or choose Drahmin and verse Raiden and do the electric grab (forward, forward, 1) Then Drahmin uses his unarmed arm for a short while.
*You can also do this with Moloch, when the electric grab is performed on him, Moloch uses his unarmed arm as well.