Planet Diver and Planetary

Planet Diver and Planetary are two single-target Psynergies of the Mars element and are among the games' most powerful single-target Psynergies. They are usable by Venus Adepts Isaac and Felix and the Mars Adepts Garet and Jenna while they are in the Brute class series.

Planet Diver
Planet Diver is described as "leap skyward and lunge onto a foe". The user leaps in to the sky and using gravity comes down on the target and attacks them. It is available to the Brute class series. Due to how powerful it is, it is extremely useful against any enemy including Saturos and later Menardi. It costs 7 PP to use and strikes the target with Mars power equal to the user's own attack power with 36 base Attack added.

Planetary
In Golden Sun: The Lost Age, after reaching the Berserker class, Planet Diver is replaced by the more powerful (and more expensive) Planetary. Planetary is described as "strike a foe with fire from the heaven". It is almost the same as Planet Diver with the only difference being that instead of looking like a meteorite coming down, the user takes on the form of a giant dragon head coming down. Despite being expensive, its pure power makes it a worthy option for single target Psynergy in the late game. Planetary costs 19 PP to use and strikes the target with Mars power equal to the user's own attack power with 98 base Attack added.

Analysis
When it can first be accessed, Planet Diver is likely the strongest single-target attack the party has, and remains so for quite some time. It is useful against a number of mid-game bosses, including the Hydros Statue and the Kraken, but becomes less so in the deserts, where most of the enemies are Mars-based. If Isaac or Garet is put in the Swordsman class series after acquiring Mia, the other will be able to use their Djinn to enter the Brute class series - combined, Cutting Edge and Planet Diver are effective against the vast majority of the game's bosses. In The Lost Age, Planet Diver is apt to see much less use, as only two major story bosses, the Aqua Hydra and Poseidon, are vulnerable to Mars-based attacks.