before the pull, people will use the invigorating shadowdust legendary to use cds on prepull, vanish, then swap gear sets to their real legendary, getting a free use of some cds, and a reduced cd on their shadow blades. There is an advanced version of this where they talent swap in prepull to get a damage buff on shadow dance as well. further increasing their damage compared to other people. Currently ~20 people in the top 40 on M guardian are using this in their logs