In Mim'krilu Skyway, after the save point, walk further until you see a big boulder of thick walls and two switches. The first is on the big floating brick and second is down next to it. Stomp on the second switch. You will see a wall that is blocking in some way rise up. Stomp on the first switch. The floating brick will move and it will bring you to an isolated place. Walk around to find some battles. If you encounter Flauros, four will appear instead of two. Note: There is a pink diamond in the middle of that isolated place. That crystal contains a very strong monster (level 90). If you find the key for the activation of that crystal, save the game first or you may lose your progress. The key is located two stages before the Boss fight with the Twin Dolls (Fior and Asia).