Use EXP Orbs to raise the levels of your characters.
You can go up to the next floor by defeating the current floor's boss, and you'll be able to go straight to that floor by talking to the NPC next to the transport device.
How to Enter
You must have an EXP Dungeon Ticket to enter the Philosopher's Tower.
1 ticket is distributed per day.(This number is reset at 0am.)
*You cannot receive any more EXP Dungeon Tickets if you have more than 6 EXP Dungeon Tickets.