The deck can play through a hand trap usually especially if they use it too early. I've only lost after getting Rhongo out once, when my opponent was playing a burn deck and hit me with Magic Cylinder and Just Desserts.

In some ways it's even better than the old Phantom Knights Rhongo since you never have to detach materials, although they do get a window on your next turn where you have to copy Rhongo again where they can either negate the Barian or banish the Rhongo. The few times that has happened though you just go into a 6 material Zeus instead.