Mithrun is quick, when he hears Ardyn cry out, to move for the source - but not quite quick enough to find a projectile to take the Intellect Devourer out (hopefully, if his aim holds up) before Ardyn's own overloaded memory does.

Instead, the thing just Does That all on its own. Mithrun is far enough to have an instant longer than Ardyn does to brace himself - but that isn't much, when it comes to the spike of pain through his skull, and the unfamiliar memory he knows is coming.