As the voice spoke into Alex's head, Alex felt like grabbing Layla, rip her gown apart and insert his rod deep into her.
However, he knew that he was in an illusion, and that, if he grabbed Layla's gown and tore it apart to shove his manhood into her, it could be the real Layla who would do to that.
He knew that was what the illusion was about, which was to simultaneously persuade and compel him to do things with the Layla in his vision. However, the Layla in his vision could then become the real Layla. And once he can do anything carnal with her, they should both forget about receiving transmission of the legacy.
So, he tried all his best to resist that coercing and persuasive, fairy-like voice that endlessly echoed in his head.
Then to destroy the continuously echoing voice in his head, he screamed "Get the fuck out of my head!!"