Hall of Specialist
This would be the go-to place to learn specific end-game fights. I’d view this as an advanced version of the Stone, Sky, Sea where it’s fight specific, but instead of just being a single long DPS check, each fight is broken into individual phases with each phase mapping to a challenge/floor. It would take place in an actual arena and it would feature a shadow version of the boss. Each floor would focus on the mechanics of each phase like:
  • AoE patterns
  • Debuffs that need to be swapped/purged
  • DPS checks
  • How to deal with adds
  • Tank busters
I don’t think there really needs to be a reward for this (being able to clear an end-game fight is rewarding on it’s own).