Basically any instant cast spell that you're about to cast on a (friendly) target ie. Life Cocoon that will cancel if that person dies before you can cast it on them. Whats happening is I'll be running across a map trying to get to someone about to die spamming Cocoon so the moment they get in range I'll cast it on them, but just as I get to them they die and I end up casting it on myself -_-