Sometimes a random phenomenon will appear in a room. They affect the room in a way that makes it harder to explore, but give a greater reward for your explorations. You can learn that the room is affected by a phenomenon from a visual effect that appears on the map or in the entrance window.
Although the phenomena appear in rooms randomly, you can also summon one by using special items that you can get in our game store.
You can banish a phenomenon after you explore the room, or by using a special item from the store.
If you banished the phenomenon by exploring the room, the mode in it will change. If you used a special item for this, the mode will remain the same.