Phaeton's Blade

Phaeton's Blade is a Light Blade found in Golden Sun: The Lost Age. It is found in a treasure chest in Jupiter Lighthouse, in the room almost completely filled with Hover panels. It can be bought for 13600 coins and sold for 10200 coins. Being a Light Blade, it can be equipped by Isaac, Felix, Garet, Jenna, Ivan, and Piers. It increases the wielder's attack by 151.

Phaeton's Blade's Unleash attack is Light Surge. Light Surge converts all damage to Jupiter damage and attacks with an additional 51 damage points. Also, there is a chance that it will cause delusion in the target. Visually, Light Surge resembles a multitude of light beams descending upon the target.

Phaeton's Blade is the second strongest weapon at the time it can be obtained (the strongest is the Rising Mace), and it isn't long until stronger weapons become available. However, Isaac and Felix's teams join forces after Jupiter Lighthouse is cleared, meaning there are twice as many Adepts to pass the Blade on to after it is replaced. Since Light Blades can be used by so many Adepts, it will probably remain in someone's possession for quite some time, perhaps even until Mars Lighthouse.

It is found again in Dark Dawn within Snowdrift Shrine. You must slide down using the 5th slide-able hole right to the left and fall down into a larger slide-able hole. It has two more unleashes: Combat Dance and Centurion. Combat Dance is not aligned with an elemental unleash but Centurion is a Jupiter-based unleash.

Cultural Reference
Phaëton was the son of Helios, the sun god. Phaeton went to the heavens to ask Helios to confirm that he was his father, and Helios swore on the river Styx that he would give Phaeton anything he asked for in order to prove this true. Phaeton requested to drive his father's chariot (the sun) for a day, and despite Helios's attempts to talk him out of it, he was adamant, and the sun god relented. However, Phaeton was unable to control the fiery horses that pulled the chariot, and first drove too high, giving the earth a chill. Then, he dipped too low, burning the vegetation, turning part of Africa into desert, and burning the skin of the Ethiopians brown. Zeus was forced to intervene by striking the runaway chariot with a lightning bolt to stop it, and Phaeton died falling into the river Eridanos.