Swordsman Class Djinni Composition
The Swordsman Class in Golden Sun is primarily available to your Mars Adepts Garet and Jenna. You're also able to become a Swordsman on your Mercury Adepts Mia and Piers but only once you've stacked 6 or more Djinni of the opposite school.
I would recommend avoiding trying to make your Mercury Adepts into the Swordsman Class though as it requires many Mars Djinni in order to accomplish this task which will severely limit your other possible group compositions.
Mars Adepts: 1 Mercury (Swordsman)
Mars Adepts: 2 - 3 Mercury (Defender)
Mars Adepts:
4 - 5 Mercury (Cavalier)
Mars Adepts: 6 Mercury; 1 Mars (Luminier)
Mars Adepts: 7 Mercury; 2 Mars (Radiant)
Mercury Adepts: 6 Mars (Cavalier)
Mercury Adepts: 7 Mars; 1 Mercury (Luminier)
A Swordsman is quite the well rounded class. They come with a decent boost in attack rating and have a fantastic mixture of offensive and defensive abilities. Ply is learned as early as level 1 with their first group heal being learned at level 8.
In addition to regular and group heals this class also receives the Protect Psynergy which will boost your allies' defensive ratings. If you're curious about the other abilities available to the Swordsman class take a look below for a full write up.
(Level 1) Ply: Heals a Single target.
(Level 2) Blast: Hits 3 targets with 25 Power.
(Level 3) Guard: Raises a single targets defense by 25%. You can stack this ability up to a maximum of 150% increased defense.
(Level 5) Cure Poison: Cures Poison/Venom from 1 ally.
(Level 6) Avoid: This ability reduces the encounter rate for you and your team.
(Level 8) Wish: Restores 80HP to the whole party.
(Level 10) Mad Blast: Hits 3 targets with 50 Power.
(Level 11) Cutting Edge: Hits a single target +32 Attack.
(Level 13) Restore: Removes Stun, Sleep, Delusion and Curse from a party member.
(Level 15) Protect: Raises the defense of your entire party by 12.5%. You can stack this ability up to a maximum of 150% increased defense.
(Level 16) Ply Well: Heals a single target for 200 HP.
(Level 22) Wish Well: Heals every member of your group for 160 HP.
(Level 28) Fiery Blast: Hits 5 targets with 110 Power.
(Level 30) Break: Removes the buffs on all enemies.
(Level 34) Pure Ply: Heals a single target for 1,000 HP.
(Level 46) Pure Wish: Heals your entire party for 400 HP.