Buddha nature misunderstood as atman.

[Sonny]

"There're two kinds of Buddha nature. One kind is permanent. One kind is impermanent. The empty nature of our own mind is permanent; the clear and knowing nature of our mind is impermanent. The clear and knowing nature is just our ability to perceive objects -- for objects to arise and for us to engage in them – the thing that makes that process happen. This is impermanent, because each moment of mind is clear and knowing and yet each moment is different from the previous moment." - Bhikshuni Thubten Chodron - http://www.thubtenchodron.org/

[Son of Buddha]

"There're two kinds of Buddha nature. One kind is permanent. One kind is impermanent. The empty nature of our own mind is permanent; the clear and knowing nature of our mind is impermanent. The clear and knowing nature is just our ability to perceive objects -- for objects to arise and for us to engage in them – the thing that makes that process happen. This is impermanent, because each moment of mind is clear and knowing and yet each moment is different from the previous moment." - Bhikshuni Thubten Chodron - http://www.thubtenchodron.org/

the Buddha nature is not-Empty,it is not empty of itself but empty of all defilements-Nirvana sutra