Oh yeah Cybernetics
I remember back in the old thread the Equestrians had developed basic level cybernetics for replacing limbs and some neuro-implants, so in ten years they could have replacement cybernetic eyes. The problem with using cybernetics to resist that is that not everybody likes them and you have to know what patterns to block out, and before getting those patterns that they even caused that effect. Also the Archmage will be resistant, but a few of his guards and the ships crew will be susceptible. While normally military is trained to resist any neurological compulsions like that a lot of there ship crew and guards are fresh recruits put into place till they can get more highly trained soldiers in to replace the losses from the Drac War.