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Reflexus, Fishman party, and I believe there was one down with the fungus folk. I am looking for a fourth to complete earth. Does it exist?
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Maybe the gem floating by the river in front of the castle by the Hub is the fourth? I have also spent an hour trying to reach it but I'm convinced that one must teleport there.
Edit:
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Aaaand I just found the ladder. Man this game can make one feel sharp and slow all at once...