Thunder Crown

The Thunder Crown is a Crown-class head armor found in Golden Sun and Golden Sun: Dark Dawn.

Basic Description by Game
The Thunder Crown increases the wearer's base defense by 40, and it increases PP regeneration by 4. However, it is cursed, meaning that the wearer cannot remove the Thunder Crown unaided, and may occasionally be immobilized during battle. It can be sold for 5625 coins and subsequently rebought for 7500 coins.

In Golden Sun, it is found in a chest in the later portion of Venus Lighthouse. In Dark Dawn, it is found in a chest in Yamata Ruins after solving a glyph puzzle. As a Crown, it can be equipped by all Adepts.

Analysis
This is very likely the best piece of headwear for whichever Adept of the party of the original Golden Sun is equipped with the Cleric's Ring to negate the negative effects of equipment curses, providing the highest Defense rating of all headwear in the first game and a useful PP regeneration bonus.

If present on the original party when they join Felix's party late in The Lost Age, however, it becomes instantly outclassed, specifically by the Crown of Glory which you can win multiples of with Lucky Medals; a Crown of Glory is exactly like a Thunder Crown, but without the equipment curse and with twice as much PP recovery.

In Dark Dawn, the Thunder Crown, like all Cursed equipment, is less useful due to the extremely late availability of the Cleric's Ring, meaning that any Adept that equips it will have to suffer through the curse throughout the main storyline. Unlike many other pieces of cursed equipment, the Thunder Crown has an advantage that makes it at least worth consideration despite the curse. The Thunder Crown has the distinction of having the highest PP regeneration of any piece of headwear, followed closely by the Mythril Circlet. The 4 PP regeneration rate is the highest that Matthew, Tyrell, Eoleo, and Sveta can achieve. However, the player must weigh the regeneration against the effects of the curse, since the Cleric's Ring can only be found after the main storyline is complete.