The Sky Tower is an area where players can obtain Magic Stones. The Sky Tower consists of 50 floors, each one of which must be completed before unlocking the next. Each floor features a boss with different special abilities, sometimes with vastly upgraded stats, and a hint indicating a strategy to use for that floor. Each floor also features a different set of Magic Stone drops.
One ticket is required for each attempt at any floor. Tickets recharge every 120 minutes, and the player can hold a maximum of 5 at once. The first time a player beats each floor, a bonus ticket is awarded (replaying a previous floor does not award a ticket).
The in-game drop list is not complete for every floor. Most floors with a higher-rank stone will also drop lesser versions of the same stone. For some floors, drops do not match the listed version of the stone (e.g. a "I" stone will always drop on a certain floor instead of the "III" stone that is supposed to drop).