Agent of Mystery

I was recently recruited by the MBI to investigate The Collective.  The past few weeks my investigations have taken me all over the grid trying to track their nefarious plot and insidious actions.  First it looked they were targeting the Mad City Bank, and now, just when I thought I had thwarted their plans, it seems they have teamed up with witches!

I will figure out what they're up to and stop them!  But for now, what do all these clues mean?