Complete Edge’s Tale and you’ll unlock Edge’s Challenge Dungeon, as per usual with The After Years. You’ll find the Challengingway on the east side of Eblan Castle; speak to him to trigger the challenge.

Edge’s Challenge Dungeon consists of four named floors, and is by all accounts a fairly normal dungeon. The trick here is the fact that the Challenge Dungeon is timed, and your prize is dependent on how quickly you make it through the Dungeon. Complete it under five minutes (or under ten minutes on the PSP) to earn the best items. Your first trip through will probably be focused on collecting the other treasures, so don’t expect a great prize. 

The chests in this Challenge Dungeon are a bit weird. They’ll reset every time, and will contain random items. The chests with monsters virtually always contain good equipment, though this equipment is also random, so there’s no saying what you’ll get (though these items come from a pre-determined list). After you’ve opened a monster chest once it will change into a normal item chest.

- 1F. The Lamias here are quite dangerous with their confusing counterattacks, so try to kill them quickly with Bands. There’s a monster-in-a-chest south of the entrance, a chest in the northeast, and another monster-in-a-chest in the northwest. There are NPCs roaming around these hallways; don’t bother trying to talk to them, as they’re here solely to get in your way. You can find a Killer Bow and an Asura on this floor.

- 2F. Be very careful of Chimera Brains here, as they can murder you in a single hit if you have bad luck. Head south and you’ll find a dead end. Go through the lower wall and you can find a passage to a monster-in-a-box. Go south through another secret wall to find another chest, this one taking so long that it’s not worth grabbing. Return to the entrance and go east two chambers; there’s a chest in the middle of the larger chamber and a secret passage in the far south leading to the hallway in the far right, including the exit. You can find a Black Belt Gi and a Mythril Hammer on this floor.

(Occasionally you’ll run into Bugs on this level. These bastards have a ton of HP, can inflict confusion, and will respond to attacks with Flare. Unless you’re trying to fill up your Bestiary it’s wiser to just avoid these things.)

- 3F. Head east, then north, then west. You’ll see two sets of stairs; pass through them to the north to find a monster chest. There’s another chest in the northwest corner of the area, and one final chest to the direct east of this second chest. Neither are really worth getting. The exit is in the northeast corner; you’ll have to go through the middle of the room, heading east, then north. You can find a Black Cowl and a Crimson Cherry on this floor.

- 4F. Watch out for groups of Lamias here. The Wild Moon Band (Tsukinowa and Edge) is invaluable for clearing them out with a minimum of attacks. There’s a spot to exit the dungeon on the left and a spot to heal on the right, though you’re so close to the end that you should just plough straight ahead. Check the last chest on the pedestal to the north, then go through the door behind the pedestal to find one final room. Grab the chest quickly in the north to end the dungeon and jump back out to Eblan Castle. You can find a Chakram and a Wind Spear on this floor.

Popping open the final chest will end the dungeon and earn you your prize. If you completed the Challenge Dungeon under the time limit (five or ten minutes, depending on your version) you’ll receive one of the items listed below. Otherwise, you’ll receive a regular item that’s totally not worth the effort.
  • Adamantite
  • Blitz Whip
  • Elixir
  • Flame Lance
  • Gaia Hammer
  • Goblin Mask
  • Kotetsu
  • Mist Wrap
  • Silver Apple
  • Soma Drop
  • Treasure Hunter
  • Wing Edge