Forgotten Village bonus content
Written by MSG Commander
Secret Arena
After completing the Normal End, you can go back to the Forgotten Village and (finally) access the building on the east side of the village.
The building contains the secret battle arena, where you can battle four different bonus bosses. (See Azyleo's Secret Arena Guide for details on when to challenge these enemies.)
Gazillion Challenge
Also, if you go to the Inn, the animals that were blocking the staircase are gone, and you can now enter the basement!
On the first floor of the basement is the Gazillion Challenge, where you get 20 turns against Maidame Curie to do as much damage as possible. (Hint: use Break Unisons that hit multiple times.)
There's also two treasure chests on the east side of the room, containing a Break Chain Arkstone and a Foxy Arkstone.
Maid Weapons
On the second floor of the basement, there are four sealed doors, each of which can be opened by using 3 Tray Gems. Each room contains one Maid Weapon, the most powerful weapons in the game. From right to left, the weapons are:
1. Laundry Pole (Freya's weapon)
(behind the right-most top door)
2. Maid Yearbook (Minerva's weapon)
(behind the middle top door)
3. Handmade Mitten (Iris' weapon)
(behind the left-most top door)
4. Maid Brand (Izayoi's weapon)
(bottom door)
If you come here right after the Normal End, you should have 6 Tray Gems, which will let you claim two Maid Weapons. You can choose any two, but I recommend the Maid Brand and Laundry Pole.
If you want to collect every treasure in the game, you'll have to claim the other two weapons eventually, but you can worry about that after you've completed the True End.