Rune Blade

A Rune Blade is a Long Sword-class weapon Artifact introduced in Golden Sun: The Lost Age.

Basic Description by Game
In all appearances, the Rune Blade increases the wielder's base Attack rating by 162 points. It can be sold for 11250 coins, and subsequently rebought for 15000 coins.

In The Lost Age, a Rune Blade can be acquired as a rare drop item when felling a Lesser Demon monster that appears randomly in the dungeon Magma Rock. It can be equipped by Felix, Piers, Isaac, and Garet. Its Unleash effect is Void Beam, with the standard base activation rate of 35%, which is a physical attack with an additional 57 points of damage added, and then the resulting damage is either increased or decreased based on how the user's Jupiter power measures against the target's Jupiter resistance. In addition, the effect may seal the target's Psynergy. The Void Beam visually resembles the wielder summoning a 3D hologram of a symbol that draws itself in front of him as the camera swirls around the battlefield, and the symbol generates a thick white-purple beam that pierces through the target.

From an endgame perspective, as a Long Sword with a Jupiter unleash, this sword falls to the Excalibur, whose 18 more Attack points, 16 more damage points, and chance to triple the resultant damage (rather than sealing Psynergy) all completely dwarf this weapon's aspects.

In Dark Dawn, the Rune Blade is forged from a Rusty Sword found in the shallow patch south of Yamata. To gain the proper Rune Blade, the player must take the Rusty Sword to Obaba, who will reforge the Rusty Sword into the Rune Blade free of charge. The Rune Blade can be equipped by Matthew and Tyrell. It gains 2 new unleashes: Life Nourish and Vorpal Slash. Void Beam remains the signature unleash.

Analysis
In The Lost Age, the Rune Blade is technically identical to the Mythril Blade in every aspect save for the fact the Rune Blade's Unleash effect is based on the Jupiter element instead of the Mythril Blade's Mercury-based Unleash. However, while there is a Mercury Adept warrior like Piers to equip the Mythril Blade for easily enhanced damage, it is harder to optimize the Rune Blade's damage potential because there are no Jupiter Adept warriors that are able to equip Long Sword-class weapons; it is at its optimum only if wielded by a Venus or Mars Adept as a War Adept. It is a good upgrade to the previous Jupiter-based weapon you will most likely find, the Phaeton's Blade, and it might end up being in the party's inventory at the game's end if the player is not playing to collect all the strongest weapons, but it is not at all an ultimate weapon like the Jupiter-based Excalibur.

In Dark Dawn, the Rune Blade can be acquired as soon as the player gains access to the ship. This early availability results in a comparatively high Attack increase for any player, while its overall power means that it can remain relevant for much of the game. However, in later portions of the game, it competes with other weapons. In Matthew's case, the Gaia Blade is the most common alternative, due to its Venus affinity. However, the player must complete several plot related quests prior to getting the Gaia Blade, allowing the Rune Blade to be a viable placeholder. As for Tyrell, the player may later choose to give him the Levatine, which gives a greater attack increase and possesses stronger unleashes. Either way, the Rune Blade is still an excellent weapon that will see use while the player is exploring the Eastern Sea.

RNG Method (The Lost Age)
1st Round (Big Arrow on the Lesser Demon):
 * Felix casts Clay Spire;
 * Jenna casts Aura;
 * Sheba casts Ray;
 * Piers casts Frost;

2nd Round:
 * Sheba unleashes Whorl;
 * Everyone else attacks the other monster.