This quest has no legend.
With the Updates/8.6 the overcharged runes were removed from tibia and replaced with golden and silver Rune Emblems. This resulted in the reward of this quest being changed from an Ultimate Healing Rune with 3 charges, to a Silver Rune Emblem (Ultimate Healing).
First of all, you have to go to the Edron Hero Cave, which is here:
When you enter to the undergrounds, you have to kill some wild warriors. Go to the next hole.
Now you have to kill some Demon Skeletons, Wild Warriors, Prietesses and Bonelords. Go with that way, and go downstairs:
Now you have to go with that way, killing some Monks, Demon Skeletons and Wild Warriors. Go downstairs:
Now you have to kill some Hunters, Demon Skeletons and Prietesses. Go downstairs.
This is the last floor, it containts 5 Monks:
The Silver Rune Emblem is in the box.