Gradually decreases the wearer's HP.
Thornlet (いばらのかんむり, Ibara no Kanmuri?, lit. Crown of Thorns) is a recurring helmet in the series. It is oftentimes one of the strongest helmets in terms of Defense, but at the cost of constantly draining the wearers HP at a rapid rate. It is usually recommended to have something with Auto-Regen to counter the Sap effect of the Thornlet.
Thornlet is the most powerful helmet, boosting +20 Defense and +5 Magic Defense, but at the cost of +4 Weight, -5 Magic, and constant Sap status. It also prevents Sleep, and can be found in the Pyramid of Moore or Sealed Temple, or stolen from Lamia Queen.
Cursed crown that gradually drains the wearer's HP.
Thornlet is one of the most powerful helmets as far as physical defense is concerned, only bested by Saucer and Dueling Mask. It provides 38 defense, but also inflicts constant Sap status on the wearer. It can be stolen from Hidon, metamorphed from Siegfried, Behemoth King (Undead), Daedalus, or Ahriman, and by betting the Force Shield in the Dragon's Neck Coliseum.
Thornlet returns in the prequel, only this time as a level 100 hairpin. It provides -21 HP, +499 Bravery, Bravery Boost on Dodge -3%, and Bravery Boost on Block -5%. It can be obtained by trading 101,320 gil, a Leo Recipe, Delicious Fish, and Nethicite.
Thornlet's Japanese name is the Crown of Thorns. In Christianity, the crown of thorns was woven of thorn branches and placed on Jesus Christ during the events leading up to His crucifixion.