I think this was a brainwashing mask or something used by the forces of evil or army of darkness (or whatever chuuni names they care to call themselves) in the SD Gundam Sengokuden series? (AKA the Musha Gundam series)
Wait.Ah!
It's the Goddess of the Forest.
Look carefully at her.
She has a Brainwashing Mask on.
And what's this army of darkness thing...
Not going to help her, eh...
This must be the work of the Army of Darkness...
'tis dangerous, so we'd best leave her alone.