Shaw’s psychic defenses are not great. Emma used her telepathic powers to capture him and arrest him. Then she later used her telepathic powers to mindwipe him.
Claremont just stupidly wrote him as the leader of the Hellfire Club. Which would have been impossible with powerful telepaths like the White Queen or the Black Queen. Though technically Selene had Shinoni kill Shaw, then she replaced him with Blackheart as Black King. She screwed him over big time twice. While he was locked up by Emma, Selene killed off Shaw’s inner circle and sent a resurrected Shinobi to kill him.
Now while I’m sure Shaw is dead doesn’t this mean he just gets resurrected unless the quiet council decides not to.