Darksword

A Darksword is a Long Sword-class weapon Artifact available in Golden Sun: The Lost Age. It is only bought randomly by bringing a Dark Matter forgeable material to the blacksmith in Yallam so that he may create one of several possible, randomly determined items from it, including this one. Being a Long Sword-class weapon, the Darksword can be equipped on warrior-style Adepts, namely Felix, Piers, Isaac, and Garet. Its buy value is 24200 coins and its sell value is 18150.

The Darksword increases the wielder's base Attack rating by 210 points, which is the highest base Attack increase afforded by a piece of equipment in the Golden Sun series. It is a cursed item, which means that if an Adept equips it, he is inflicted with an equipment curse which causes him to be physically unable to de-equip it without assistance from a healer at a Sanctum. Also, if he is not equipped with the Cleric's Ring then when in battle there is a chance he may be immobilized, unable to do anything whenever he attempts a battle command. Its Unleash effect is Acheron's Grief, with the standard base activation rate of 35%, which is a physical attack with an additional 76 points of damage added, and then the resulting damage is either increased or decreased based on how the user's Venus power measures against the target's Venus resistance. In addition, the effect may inflict the Venom status condition on the target. Visually, Acheron's Grief is one of the more spectacular Unleash effects in Golden Sun: The Lost Age, which resembles the wielder summoning a colossal purple-hilted sword crashing down into the area where the target is, letting loose a veritable water spout of purplish-blue energy as it digs into the target, and detonating in a large explosion of dark energy as the screen temporarily inverts its color. Effectively, it looks like a purple-colored Titan Blade. In Dark Dawn the Darksword gains 3 new unleashes: Mortal Danger, Spiral Assault, and Sky Diver.

There is no denying that a Darksword is a strong weapon, granted. It has the highest attack rating of all weapons, and its Unleash effect is stronger and more potentially desirable than any weapon that comes before it thanks to its chance to inflict the powerful Venom status condition. It would have been considered one of the best weapons in the game if it weren't for the fact that a select few weapons in the game achieve "ultimate" status because they have Unleash effects that overpower everything else in pure damage terms except summon sequences; namely, the Sol Blade, the Excalibur, the Tisiphone Edge, and the Masamune all outright multiply the damage they do with their Unleashes, whereas the Darksword is merely one of the strongest of the weapons that simply add damage points with their Unleashes. (Note that it has the third highest damage point increase for an Unleash effect in the game; the second highest is the Atropos Rod's 114 damage points and the Lachesis' Rule's 125 points.) If you are not playing The Lost Age for the sake of amassing all manner of ultimate equipment, then if you manage to forge a Darksword during a game where you transferred full party data from Golden Sun so that Isaac's party joins with the Cleric's Ring in its inventory, then this is a great weapon for a Venus Adept to use and would be equipped in the party by the time the game is complete.

Cultural References
In Greek Myth, the river Acheron ("stream of woe") was believed to be a branch of the underworld river Styx over which Charon ferried the newly dead souls across into Hades.