Warden tells you, "In the swamps outside Shoushi you'll find the resting place of the once great Green Mire Warrior."
Warden tells you, "You will need to discover a number of keys and use them to traverse his final resting place."
Warden tells you, "Return to me with the Green Mire Yari or the Green Mire Cuirass and I'll reward you for your work."
Warden tells you, "After finding the broken Yari or Cuirass you can have them repaired by Hiro Ishigame."
Warden tells you, "You'll need to do this before I can reward you for them."