In Ultimate Truth there are no Buddhas and no demons;
One enters here the Realm where Dharma is exhausted.
Among all Vehicles, this ultimate teaching
Is found only in the Tantras.
It says in the Highest Division of the Tantra:
“When the various elements gather in the Nadis,
One sees the demon-forms appear.
If one knows not that they are but mind-created
Visions, and deems them to be real,
One is indeed most foolish and most stupid.”

Milarepa (1052-1135 , Tibetan Yogi and Poet)