Assassin Blade

An Assassin Blade is a Light Blade found in Golden Sun and Golden Sun: Dark Dawn.

Basic description by game
An Assassin Blade increases the wielder's attack by 90 points. It can be and sold for 5850 coins and subsequently re-bought for 7800 coins. In, Golden Sun, it is one of the prizes that can be won in the Lucky Medal Fountain in Tolbi, and can be equipped by Isaac, Garet, and Ivan. If it is transferred to Golden Sun: The Lost Age, it can be equipped by Felix, Jenna, and Piers.

The Assassin Blade's Unleash attack is Mortal Danger. Mortal Danger is a physical attack that adds 28 damage points, and then modifies the resulting damage by how the user's Venus power compares to the target's Venus resistance. Also, it has a small chance to instantly kill a target, an undeniably powerful effect. Visually, Mortal Danger resembles a normal strike with an image of the Grim Reaper behind the attacker, much like the Condemn Psynergy.

In Dark Dawn, the Assassin Blade is found in a chest in Belinsk's library, accessible by solving a simple bookcase puzzle. It can be equipped by Matthew, Tyrell, Karis, Amiti, Eoleo, and Himi. Due to the revisions to the Unleash system, the Assassin Blade has gained one additional unleash: Critical Move. Critical Move is a non-elemental physical attack that multiples damage by 1.4. Mortal Danger remains the signature unleash, and retains its characteristics from Golden Sun.

Analysis
The Assassin Blade is the strongest weapon that can be won at the fountain (although its being a Light Blade doesn't help matters for Mia, and one may wish to consider that its unleashed power is Venus-based), and its instant kill effect makes it perhaps the most desirable prize from the Tolbi Spring. It is also the strongest weapon for when it can be obtained. Stronger weapons don't appear until Lunpa, and the Assassin Blade may be used even afterwards considering Mortal Danger's extra effect.

When the Assassin Blade's extra effect occurs, the enemy will turn entirely white upon death (rather  than the usual greyscale), and the words "[enemy]'s spirit was drained"  will appear. However, a small glitch can occur if the enemy is felled by Mortal Danger due to damage (and not the instant-kill) in that the enemy's image will still show up as completely white despite the KO (and associated text) being entirely normal.

In Dark Dawn, the Assassin's Blade is a powerful weapon when first discovered. Since its Unleashes are now randomly chosen, the chance of instantly felling a target is much smaller. The Assassin Blade's Venus-based Unleash makes Matthew an instant candidate for equipping it. However, the player may wish to let him retain the Grievous Mace collected earlier, as it is a Venus-based pure-element weapon or let him wield the stronger Sword of Dusk. Thus the Assassin Blade is likely to fall in the hands of Karis or Amiti.

Even after the Adepts gain access to stronger weapons while exploring Morgal, it is still worthwhile to keep the blade in the inventory so that it can be given to Eoleo after he joins the party. The Assassin Blade is an immediate upgrade to the Broad Axe Eoleo starts out with, and is a decent placeholder until the player gains access to stronger weapons. After this, the Assassin Blade will quickly be outclassed by the forgeable weapons and artifacts available and should be sold off.