Master Rapier

A Master Rapier is a common Light Blade-class weapon featured in the Golden Sun series.

Basic description by game
A Master Rapier increases the wielder's base Attack by 86 points. As a common item, it can be bought repeatedly from vendors for 6800 coins each and can be sold for 5100 coins each. In Golden Sun, it is sold in the towns of Tolbi, Lunpa, and Lalivero, and can be equipped by Isaac, Garet, and Ivan. In Golden Sun: The Lost Age, Master Rapiers are sold in the towns of Champa and Contigo, and can be equipped by Felix, Jenna, and Piers.

In Golden Sun: Dark Dawn, Master Rapiers have acquired three Unleashes as part of the revisions to the Unleash system: Critical Strike, Spin Strike, and Double Attack. Critical Strike is a non-elemental physical attack that multiplies the resulting damage by 1.5. Spin Strike and Double Attack are physical attacks that convert all damage to Jupiter damage. Spin Strike will hit three targets, while Double Attack multiplies damage by 1.6. Master Rapiers are sold in the towns of Belinsk, Saha Town, Harun Village, Yamata City, and Tonfon, and can be equipped by Matthew, Tyrell, Karis, Amiti, Eoleo, and Himi

Analysis
In Golden Sun when it can be first bought in Tolbi, it is generally not a worthy purchase because  you can find many better weapons in Tolbi by playing the Lucky Spring minigame with your Lucky Medals, such as  the Assassin Blade, which has an even higher attack rating and an  Unleash effect that may instantly kill an enemy. Other weapon artifacts that you can get in place of Master Rapiers are Burning Axes and  Grievous Maces from the same spring, and if you explored the first few levels of the Crossbone Isle dungeon  during your trip on the Tolbi-bound Ship, you may have the  Mystery Blade on you as well.

In Golden Sun: The Lost Age, much of the game's focus is on completing puzzles in the dungeon-style locations that provide as rewards weapon artifacts far superior to commonly bought weapons and even weapon artifacts that can normally be bought in vendors. When you first gain the Lemurian Ship and can sail the Great Eastern Sea, the Master Rapiers you can buy at the town Champa do indeed have a somewhat higher physical attack rating than the weapon artifacts you may have amassed at that point such as the Disk Axe, but considering the frequency of how you can get newer and stronger weapon artifacts while journeying throughout the Great Eastern Sea and its many locales, you might as well not bother with Master Rapiers. In point of fact, the Ninja Blade light blade Artifact you can buy at the town Izumo which becomes available to you at the same time as Champa is a far better weapon.

Note that if The Lost Age is being played without any data transfer or with a Password that's either Bronze or Silver-level, when Isaac's party joins Felix Ivan will be equipped with a Master Rapier, which is of course far inferior to the equipment Felix's party will surely have amassed by that point.

In Dark Dawn, the Master Rapier will be equal to or weaker than many of the weapons the player has when the Rapier is first available. It will very quickly be outclassed by the artifact weapons that the party will be able to acquire. Thus, the Master Rapier is not likely to see much use, as there are many better weapons available throughout Morgal. Should the player choose to use it for any reason, it is best to equip it on Karis or another Adept who has Jupiter Djinn set, due to the two Jupiter based Unleashes of the weapon.