The Fallen Squires are running wild on this island. Maybe you can participate?
Loot and Tips
Each Fallen Squire may drop an Ice Rose, Sea Sapphire Dust and/or the recipe for Swiftness Potion II. Only when (and if) you find that can you craft the flask. The Fallen Squires drop ice roses and sea sapphire dust at random rates which can make farming the ingredients a problem since you can end up with dozens of one and neither of the other. This ingredients are much more easily farmed during the Rattling Bones event.
If possible, bring 2x Ice Rose and 4x Sea Sapphire Dust with you when traveling to the island. This way, you may craft the Swiftness Potion II easily and use the event only to acquire the recipe for Swiftness Potion II.