I can't believe we got an enemy with a fancy looking clothes.
Old characters don't suddenly become relevant in this series. You're introduced, briefly important, then either forgotten or relegated to brief comedic relief from then on. There will surely be a new girl introduced to help Touma out when that happens.
apparently that is saint germain whom may or may not be multiple people. also niang niang i believe is just out of shot because the guy who took the picture did that.