Acts 19:16

And the man in whom the evil spirit was leaped on them, and mastered both of them, and prevailed against them, so that they fled out of that house naked and wounded.

Mastered both of them ... Apparently, only two of the seven brothers were involved in this episode, as indicated by the word "both." Their defeat was sudden, dramatic, and overwhelming. As Bruce said,

They employed the name of Jesus in an attempt to imitate Paul's exorcism; but when they tried to use it, like an unfamiliar weapon wrongly handled, it exploded in their hands.[24]

Many have noted an element of humor in Luke's words here to the effect that "casters out" were themselves "cast out"!