It’s interesting how the Dragon Quest magi, shamans, sorcerers, and related enemies have that bat symbol on their cloaks in every game they appear in. They first appeared in DQ II, and Hargon had the same symbol on his cloak. The evil priests in later games aren’t following Hargon anymore, so I’d like to think that this symbol is that of their cult worshiping Malroth, god of destruction. Though Malroth isn’t important to the story anymore, his followers are still out there, awaiting his return.