Beastform

 Beastform is a Jupiter Psynergy that was introduced in Golden Sun: Dark Dawn. It is notable in that using it gives the caster access to a unique class series, the Wild Animal class series.

Basic Description
Beastform is a unique Psynergy unique to the beastman Jupiter Adept Sveta. Unlike most other Psynergies, it can only affect only the caster. Beastform physically transforms Sveta into a beast-like version of herself, reminiscent of a purple werewolf, which is described in-game as "Sveta embraced the beast within." Sveta has access to Beastform regardless of class.

Beastform costs 8PP to cast, and becomes unavailable while its effect is in place. Besides the physical transformation, Sveta's class becomes the Wild Animal class series, which grants her tremendous attack and HP, but lowered PP, as well as a different set of Psynergy. As a cost of using Beastform, any Djinn that Sveta may have in her possession become temporarily unusable. This is because the duration of Beastform is limited to the number of set Djinn in her possession. Sveta will resume normal form, once the battle ends, Sveta faints, or after she has spent turns equal to her number of set Djinn. After retunring to normal form, the in-game text reads "Sveta resumed human form". In addition, for each turn spend in Beastform, one of Sveta's Djinn will be placed in recovery. If all of Sveta's Djinn are in recovery, she will not be able to access Beastform until the Djinn recover.

Analysis
Beastform is an extremely unique Psynergy, being the only Psynergy that will change an Adept's class on demand. Additionally, Beastform is accessible from any class, making it easily accessible. Due to Beastform's Djinn requirement, it is generally reserved for boss battles, which take longer, thus allowing more time to take advantage of the form. Using Beastform gives Sveta several new Attack options, which are detailed on the article for the Wild Animal class series.