Bzaro

Recruiting
In order to unlock Bzaro, you must first complete the story mission in Oldebzar. This will add Restful Stones to the map; completing its story mission will add Bzaro to your roster. It is important to complete this mission before the story mission in Cataracta Citadel. This will prevent the encounter in Restful Stones from being completed, which will permanently lock you out of recruiting Bzaro. Since Bzaro is required for unlocking all 4 Henge Fragments, this will also prevent you from recruiting a Secret Character and getting both of the game's 2 endings.

Bzil Classes
As a Bzil, Bzaro is only able to use Bzil Classes. He begins with Vangal, Therva, and Daodrenner unlocked, and must collect monster essences to unlock all of the others. Monster essences are awarded for every monster killed in a battle Bzaro was deployed in. It is not required for Bzaro to make the kill or even be alive at the time. Essences are awarded after the battle, 1 per monster tier (a tier 2 monster will give 2 essences, etc). This means a battle with fewer than 5 monsters can, and often will, still yield the full 5 essences to unlock a monster class. Killing enemy Bzil will also award 1 essence based on their primary monster class. Gathering monster essence for a monster class Bzaro has already unlocked gives him bonus AP in that class.

Bzaro's stats are solely based on his level and current primary class. This makes Bzaro especially versatile compared to human characters who have specific stat growths for each class. Because of this, there is no point in resetting his level to 1 at the Guild (although the game still lets you do so if you wish).

With Missions and Monsters installed, Bzaro also gains Vicarious AP from monsters - each monster gives a portion of their AP earned to the corresponding Bzil class. In addition, Bzaro can also gain access to the Victory Dance passive after completing a specific chain of Missions in the guild. Bzaro will similarly receive 15% of AP earned by monsters from Missions.

Trivia
Many cutscenes in the game can change based on whether or not you have recruited Bzaro. To see the most potential dialogue with him, you may want to consider immediately doing the Restful Stones story mission when it is available.