Blue Dragon enemy line

The Blue Dragon and Cruel Dragon are two powerful species of monsters found in Golden Sun: The Lost Age. These monsters, resembling large squat dragons, are palette swaps of each other and have differing levels of power and defense. This monster line is notable because both of its members can drop a rare weapon, one of which is often considered to be the best weapon in the game. The Blue Dragon monster line is also of the Mercury element due to its resistances and abilities.

Blue Dragon
A member with blue skin (obviously) and an orange underbelly, horns and wings. They has 408 HP, no PP, 349 Attack, 121 Defense, 133 Agility, and 23 Luck. Its suceptible to Mars Psynergy and resistant to Mercury Psynergy.

Blue Dragons uses physical attacks and the monster skill Ice Breath for moderate Mercury damage to multiple Adepts.

Slaying a Blue Dragon rewards you with 490 EXP, 297 coins, and seldomly a Rising Mace. They are located in the Jupiter Lighthouse.

Images from a beta version of the original Golden Sun reveal that Blue Dragons were originally coded as common enemies in that game, but were taken out to appear in the sequel.

Cruel Dragon
A member with purple skin and a green underbelly, horns and wings. It has 636 HP, 65 PP, 539 Attack, 216 Defense, 162 Agility, and 26 Luck. Its suceptible to Mars Psynergy and resistant to Mercury Psynergy.

Like the Blue Dragon before it, Cruel Dragon is a force to be reckoned with. It knows the same attacks as its counterpart, but also has access to the Freeze Prism Psynergy for heavy Mercury damage against many Adepts at a time.

Slaying a Cruel Dragon rewards you with 661 EXP, 358 coins, and in extremely rare cases, a Tisiphone Edge. They are located in the Islet Cave and are the second strongest enemy there (with Druj being the first).