Following Augustine, St. Thomas claims that forms flow from the divine mind in two ways: on the one hand into entitative existence, on the other hand into the intellect of the angels (and given that bodiless things cannot not know by abstracting, it’s hard to see what other account one could give). But in flowing into the angels, they are received not only as speculative but also as practical, not only as science but also as moral. In this sense the angel constitutes and becomes involved in the entitative nature of things from within so far as this existence is the terminus of a practical or moral action.
At the bare minimum, this saves us from the ultimately fantastic idea that the angelic custody of the world consists in their flying after things and pushing them around, but we need a better account of what this action consists in. What does the essence of things around us consist in given that the things around us trace back to the divine mind through the mediation of other practical intellects?
And yes, since this is a statement about the angelic nature, it is true both of the good angels and the demons.