trap card question

Nitwit outwitis it says discard one monster cardto target one face up monster on the fiel It loses atk equal to the discarded monsters original atk is this permanent or

it is permanent until the target leaves the field or is flipped face down

Thanks

Lingering effects will cease to linger once the target is no longer valid, as in, if the monster is no longer face-up or is removed from the field.

Thanks

answered, locked.