Required Baselevel: 40
Required Items: 20 Heart of Mermaid, 10 Leopard Talon, 3 Ancient Lips
Quest prerequisites: Bathroom Blonde (Access to the Brasilis Dungeon)
Reward: 2 Purification Potions (heals 400 HP), optional Crit +10 for 60 minutes

This is a preliminary version - we'll test the quest when it will be implemented on fRO xD.

This quest can be repeated and has a 24h cooldown.

Talk to the Shaman Anori in the northeast section of the city at 315, 334 (at the lift). She will tell you that a water nymph, a Iara, seduces the young men of Brasilis and that they disappear...

She could only break this spell with a Purification Potion and asks you to gather the ingredients for that potion (Oh yeah, we knew it... xD). The necessary items are:

20 Heart of Mermaid (e.g. from Iara, Brasilis Dungeon 2)
10 Leopard Talon (e.g. from Jaguar, Brasilis Field)
3 Ancient Lips (e.g. from Piranha, Brasilis Dungeon 1)

Bring her the needed items and she will brew 2 Purification Potion for you.

Comment: From this step on it is mandatory to have done the quest Bathroom Blonde (Access Brasilis Dungeon) ! ("Cheating" only was possible for the items' gathering xD)

Now enter the Brasilis dungeon and go into the second level to find the water nymph Iara at 157, 74 and use one Purification Potion on her.

The spell will be temporarly broken and as reward for your nice action Iara will give you a buff: You'll get Crit +10 for 60 minutes.

Comment: But if you don't have a Purification Potion with you when speaking with the Iara, you'll get a slap into your face: This action will grant you confusion or curse for 1 minute.

Sources:
pRO Update Notice
Asiasoft Library
IRO Wiki