There are many different types of ritual actions explained in the various tantras, so this is not that unusual. You can read all about psychic combat in the Biography of Ra Lotsawa, and the thing to bear in minds that Dorje Shugden will allow certain things get through to us as part of our training, and it is especially worth considering how loss of mindfulness of the Dharma renders the practitioner vulnerable to some extent, whereas doing various protection practices will have power to greater or lesser extent depending on the concentration of the practitioner. Don't think for a second that psychic attack is not being perpetuated by anti-Shugden people, and it is in the best interest of Shugden practitioners to maintain mindfulness and concentration on the Dharma, especially protection practices, not just because of such psychic attack, but there are many other hindrances and forces that need to be kept at bay until we are strong enough to transform them into the path.