Without having felt the energy to see what’s going on, no, the impression I have is that the spirit is INVOKED into the person.
They’re not making a cake out of ingredients, it’s not like that. Nothing is taken away from either being. It’s more like a venn diagram where parts are encouraged to overlap, which causes resonance, and the person starts resonating like the being.
I don’t call whatever this is a “binding”. It’s not a binding as far as I’m concerned. And there would be no physical aspect either - that could occur as the energetic effects, if they last long enough, manifest in the physical over time.
There’s some fancy marketing noise here that I would not use, but that’s their business - they’re trying to explain advanced esoteric concepts in two lines to muggles, for a very serious and deeply personal working, so they do what they can to get across the import of it.
If you look up what invocation is that might help.