FACT You get 1 for a normal clear and 3 for an expert clear. if you get the fieldwork that gives you the bonus you get ONE EXTRA, ONCE A WEEK. WHoever thought this was a good idea needs to be dropped in an asylum. EDIT: Nvm lmao, was thinking Reflective Flakes from the exotic mission. Tomb flake drop rate is pretty -blam!- tho.