Banshee generated a psionic field which protected him from the detrimental effects of his sonic vibrations, though his sonic powers could still injure him when pushed beyond safe limits.
A gifted detective, veteran undercover operative, and formidable unarmed combatant, Cassidy was an excellent marksman and a competent amateur machine-smith, well-versed in combat strategy & tactics, and teamwork drills, from his training at Interpol.