Do you mean to say that this spirit of “Universal Self” can then posess a body when someone stretches to touch their toes or spread their arms, or sit with their legs crossed, or for that matter even stand up straight as in Tadasana?
Yes, there are parts of eastern mysticism incompatible with Christianity just as there are parts of everything incompatible with christianity. It is the philosophy that is incompatible.
And as for Fr Amorth: here is something to consider by Fr Francis Clooney:
First, mere recriminations against the religion of another are just about never acceptable or useful. No Catholic likes it if the Eucharist is written off as merely “priestcraft” or “patriarchal machinations” or even the venerable “hocus pocus,” and it is hard to imagine that it helps in any way to burden the millennia-old theory and practice of yoga with the deadly charge of being Satanic. And it is a really bad idea to insult a nearly billion Hindus – who see Hinduism as having a special affinity to yoga – by charges of Satanism that echo centuries of heated Christian attacks on Hinduism, and I hope Church leaders in Rome have instructed Fr. Amorth not to make such sweeping charges.
Second, if one is a professional exorcist, one may indeed see everything in light of that profession, and so it is not surprising that Fr. Amorth sees the devil at work everywhere; perhaps it is his default explanation of the woes that afflict us. Others might appeal to literary or philosophical measures of worth, but the exorcist sees things in his own way. To others this will seem odd, exaggerated, and this is all the more reason to be careful when speaking to a wider audience who do not share one’s profession or expertise, but see the world through other legitimate lenses.
Francis X. Clooney, S.J., is the Parkman Professor of Divinity at Harvard Divinity School, where he has taught since 2005, after teaching for 21 years at Boston College. Since 2010 he is the Director of Harvard’s Center for the Study of World Religions. He is the author most recently of Comparative Theology: Deep Learning Across Religious Borders (Wiley-Blackwell, 2010), and of the forthcoming His Hiding Place is Darkness: A Hindu-Catholic Theopoetics of Divine Absence (Stanford University Press). He was the first president of the International Society for Hindu-Christian Studies, was elected a member of the British Academy in 2011 and, from 1998 to 2004, was the coordinator for interreligious dialogue for the Society of Jesus in the United States.
americamagazine.org/content/all-things/fr-amorths-yoga-and-devil
They work for the Vatican! 
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