Siren enemy line

Siren, Succubus and Nightmare are species of monsters found in Golden Sun and Golden Sun: The Lost Age. These monsters, resembling attractive female humans with long hair, are palette swaps of each other and have differing levels of power and defense. They're associated with the Mercury element.

Siren
A member with pale skin, orange/brown hair, a green dress and purple boots. They has 116 HP, 12 PP, 107 Attack, 27 Defense, 54 Agility, and 9 Luck. They are most resistant to the Mercury element and weak against Mars-based attacks and psynergies.

Siren's attack arsenal includes physical attacks and the monster skill heartrender. Psynergies include Froth for Mercury damage and Sleep, which can put several party members to sleep. Its PP rating limits its flexibility with these Psynergy moves.

Killing a Siren rewards you with 45 EXP, 56 coins, and sometimes some Crystal Powder. It is only located in Mercury Lighthouse. Compaired to some other monsters in the area, such as Lizard Man, they are somewhat easier to dispatch despite having slightly higher statuses.

Succubus
A member with pale skin, blue hair, a light green dress and pink/red boots. Only one exisits in the game; it is the second sub-boss on Crossbone Isle and is backed up by two Grislies. It has 529 HP, 56 PP, 195 Attack, 49 Defense, 101 Agility, and 12 Luck. Some of its statuses are lower than Nightmare's because, through the secret route to Crossbone Isle by the Tolbi-bound Ship, it is possible to fight the Succubus before its lesser counterpart. Again, it is most resistant to the Mercury element and weak against Mars-based attacks and psynergies.

Succubus's attack arsenal includes physical attacks and the monster skill Heartrender. It's psynergy options are different and includes Hail Prism for Mercury damage and Wind Slash for Jupiter damage, both which targets multiple Adepts. Its PP rating limits its flexibility with these Psynergy moves.

Killing Succubus rewards you with 101 EXP, 143 coins, and some Crystal Powder. Taken together with the other enemies, the total battle rewards would come out to 587 EXP and 1543 coins. As far as statuses goes, its a bit weaker than the Grislies that accompany it, except for its agility. If Djinn Summons are deployed by the entire party, it will likely fall within a single turn.

Nightmare
A member with pale skin, pink hair, a purple dress and green boots. They have 258 HP, 28 PP, 287 Attack, 89 Defense, 138 Agility, and 13 Luck. They are most resistant to the Mercury element and weak against Mars-based attacks and Psynergies.

Nightmare's attack arsenal includes physical attacks and the monster skill Heartrender. Its Psynergy options are different from its counterparts and include Fireball for Mars damage, Shine Plasma for Jupiter damage (both of which target multiple Adepts) and Bind, which seals an Adept's Psynergy. Its PP rating limits its flexibility with these Psynergy moves.

Killing a Nightmare rewards you with 241 EXP, 198 coins, and seldomly a Healing Ring. In Golden Sun it is located in Suhalla Gate, the road to Babi Lighthouse and the first part of Venus Lighthouse. In The Lost Age they are only located in Trial Road.