"Another indication of the Celestials' power is that when the Fourth Host left Earth, they eradicated all evidence of their recent and past presence from the minds and records of mortal men. Only the Eternals, Deviants, dimensional gods of Earth, and a handful of human beings are now aware of their existence and member the nature of their visits'
Do the GL's rings protect against mental attacks? If not, this isn't even a fight. And even if they do, it's doubtful they're wills are strong enough to resist Celstial telepathy.