Volcano Psynergy series

Volcano (ヴァルカン, Vulcan), Eruption (イラプトヴァルカン, Erupt Vulcan), and Pyroclasm (ブラストヴァルカン, Blast Vulcan) are a series of Mars Psynergy featured throughout the Golden Sun series. Prior to Golden Sun: Dark Dawn, the Volcano series's visual effects were shared with the Lava Shower Psynergy series, available to the Samurai class series.

Basic Characteristics
Volcano is an offensive, single-target Psynergy, while Eruption and Pyroclasm are offensive, ranged Psynergies. The total amount of damage is determined by comparing the user's Mars Power to the target's Mars Resistance and using this value to modify the base power of the particular Psynergy.

In Golden Sun and Golden Sun: The Lost Age, the series's visual effects feature cylindrical pillars of fire that erupt below the target. Volcano shows one pillar, while Eruption shows two, and Pyroclasm shows four. In Dark Dawn, the visual effects are more detailed. For each stage, the ground below the targets cracks, and a large mass of fiery lava emerges. A column of lava erupts from the mass to strike the targets. The mass of fire and the resultant eruption become progressively larger for each successive stage.

Availability
The Volcano series is available to the Guard class series, Page class series, Ranger class series, and both versions of the Pilgrim class series (Jupiter and Mercury), specifically to the stages of Ascetic or higher. Thus, only Venus Adepts are unable to access the class. Mercury and Jupiter Adepts require at least 4 or more Set Mars Djinn to access the series. Tyrell and Garet can access the class in their base Guard class, which requires no or only Mars Djinn. However, all Mars Adepts can access the class by Setting large amounts of Jupiter or Mercury Djinn. In all cases, Volcano will be learned at Level 8, while Eruption is learned at Level 22, and Pyroclasm is learned at Level 48.

Analysis
General: The Volcano series is ultimately one of the stronger Mars-based multi-target Psynergies. Volcano is a decent single-target Psynergy early on, while Eruption and Pyroclasm are excellent for weakening larger numbers of enemies. Due to its power and wide-availability compared to other options like Dragon Fume, Searing Beam, and Dire Inferno, Pyroclasm is considered one of the staple endgame Psynergies and will be used in some form or another.

By Game
Golden Sun: Garet will learn Volcano just before reaching Mercury Lighthouse, where it is a useful option against the variety of monsters inhabiting the area. Eruption will be Garet's most powerful multi-target option for a typical end-game party, but can run into issues as the major bosses are resistant to Mars. If Ivan or Mia is a Ascetic, they will acquire this Volcano shortly before the Kraken fight, though will miss out on several prior Mars weak bosses.

Golden Sun: The Lost Age: Prior to the Reunion, players will be required to change classes in order to use the series. As Jenna has her own powerful ranged option in the Beam Psynergy series, Sheba and Piers would be the more likely candidates, particularly against the Mars-weak bosses Aqua Hydra and Poseidon. Pyroclasm will be Garet's most powerful Psynergy in his base class during the later portions of the game, though the wide availability means other Adepts will likely have access to it due to class changing. Due to Garet's lower PP pool, the number of uses of Pyroclasm may be limited.

Golden Sun: Dark Dawn: Tyrell's Volcano is a good early option. Meanwhile, Eruption will be a useful option while exploring Morgal. Pyroclasm completely outclasses Supernova in both PP cost and power, and so it will be his main ranged option during the later portions of the game.