On May 9 in Persona 3 Reload, you'll get to go through your first Full Moon Operation during the Dark Hour. Instead of going up Tartarus like usual, the crew will have to go onto the Monorail train platform and defeat a boss Shadow called the Priestess. On the way to the front of the train to fight this boss, though, you'll need to defeat some smaller Shadows --such as Heat Balance and Spurious Book. Finding these creatures' weaknesses can be difficult, but this guide will help.