Binding spells are certain spells that, depending on the purpose of the casting, will "bind" things such as people and powers.
Thea and Blaise Harman's binding spellEdit
This kind of binding spell is a love charm that makes two people fall in love with each other. It requires two dolls representing the couple to be bound, as well as personal items of the two people, such as a hair  or a ring . Thea and Blaise cast this spell on Eric Ross and a human girl named Pilar, so as to make Eric forget his feelings about Thea. However, it was unsuccessful, as the soulmate principle was able to overpower the magic of the spell on Eric. 
Sylvia Weald's binding spellEdit
This kind of binding spell suppresses the power of a Wild Power's blue fire, though Sylvia Weald was presumably capable of modifying it to bind a vampire's powers, rendering them essentially human. The spell's ingredients are unknown, but they can be obtained from a Circle Midnight witch. Tormentil Redfern originally had a witch noblewoman to place the binding spell on Delos' blue fire, as a means of manipulating his son's power for his own gain. Sylvia later took on the responsibility of binding Delos' powers, which she fashioned as a kind of arm brace (though the spell still remained intact even if the brace was removed).
When Hunter Redfern had Delos imprisoned along with Maggie Neely, Aradia, Jeanne McCartney, and P.J. Penobskot, it was discovered that only the witch who cast the binding spell can undo it. As they're about to be hunted down by Night People of the Dark Kingdom, Aradia invokes Hellewise and tries appealing to Sylvia. After being declared a true "daughter of Hellewise" by her ancestress, Sylvia removes the binding spell from Delos, but is immediately killed afterwards for her treachery by Hunter Redfern's orders.