Banshee

As Black Torn Cassidy with the help of Gladiator and Juggernaut abducted Lilandra, the X-Men have attempted to save him by Professor X mentally contacting her. The Gladiator then intervene and destructed their mental connection. All that Professor X can remember was a dragon and a stag. Moira thought that his vision has no significance about Lilandra until Banshee told them that his vision is the trademark of the Cassidy family. He accompanied the X-men to their castle and found his younger brother Black Tom after defeating some zombies. The two brothers then fought but none of their powers will work against each other so they have no choice but to fight each other fist to fist. All the X-Men had a hard time fighting against Black Torn's alliances for the strength that they possess. The situation only ended when Jean Grey appeared in the scene while being consumed by the Phoenix.

Origin
Sean Cassidy was a young rich mutant with undiscovered powers. His parents died, leaving him and his cousin Black Tom Cassidy with a huge fortune and the castle they had grown up in, called Cassidy Keep, although as Sean was the rightful heir, he gained all of it. The castle was a strange place, where leprechauns lived under the protection of the Cassidy Family. Both Sean and Black Tom were mutants; Sean's power was a sonic scream.

Power and Abilities
Banshee is a mutantwhose superhumanly powerful lungs, throat, and vocal cords could produce a sonic scream for various effects, in concert with limited, reflexive psionic powers which directed his sonic vibrations. He could hover or fly at the speed of sound, and could carry at least one passenger. He could overwhelm listeners with deafening noise, stun them with tight-focus low-frequency sonic blasts, plunge them into a hypnotic trance, disorient them, nauseate them, or simply render them unconscious. Using sonic waves, he could rapidly vibrate himself or other masses at will. He could generate sonic blasts which struck with tremendous concussive force, liquefying or outright disintegrating targets at his highest levels of power. By radiating sound waves outward and reading the feedback, he could locate and analyze unseen objects in a sonar-like fashion. By modulating his scream's harmonics, he could confuse most scanning equipment. He could instinctively analyze, replicate, and block sonic waves or vibrations from other sources.

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. His physiology seemed fully vulnerable to conventional injury when his sonic powers were not engaged. Banshee had selective hearing, enabling him to focus upon, enhance, or totally block out any given sound in his environment; this shielded him from the deafening sound of his own screams, and made him a superhumanly acute eavesdropper in surveillance situations.