Mystery Blade

The Mystery Blade is a Light Blade found in Golden Sun. It is found on the second floor of Crossbone Isle. It can be bought for 6400 coins and sold for 4800 coins. Being a Light Blade, it can be equipped by Isaac, Felix, Garet, Jenna, Ivan, and Piers. It increases the wielder's attack by 84.

The Mystery Blade's Unleashed power is Life Nourish. Life Nourish converts all damage to Venus damage and attacks with an additional 25 attack points. Also, it has an excellent chance to heal the attacker by an amount equal to the damage dealt. Life Nourish appears as a swarm of gold motes of energy being pulled from the target to the attacker at the moment of contact.

While likely to be more powerful than anything found up to the earliest point Crossbone Isle can be accessed, Mystery Blade suffers from the fact that that point is right before arrival at Tolbi. In other words, the Assassin Blade, a stronger weapon with an instant-kill Unleashed power of the same element, is very likely to be gained shortly thereafter. While Life Nourish's Drain effect occurs far more frequently than Mortal Danger's Condemn effect, the higher attack bonuses of both the base weapon and Unleashed power are likely on their own to out-prioritize the Mystery Blade.