I'm playing Enigmatica 2, but I believe this is solely a Ender IO bug. I have Empowered V in my "storage" slot on my dark boots in the dark steel anvil, and when I shift-click it while it is in the anvil storage slot it fills all the empty slots in my inventory with copies of itself. Now, don't get me wrong: I love having free Empowered Vs; however, I don't feel right using them when they're probably not supposed to be there. :)

• EnderIO: 5.1.52
• EnderCore: 0.5.72
• Minecraft: 1.12.2
• Forge: Latest
• SpongeForge? yes
• Optifine? no
• Single Player