Familiars

A familiar is a creature that was captured by a player. To capture a creature, a player must kill it using a control crystal. The crystal then absorbs the creature's soul, which is bound to the wielder of the crystal (If a creature is not killed by a crystal, the crystal is destroyed). This means that familiars can be traded around by trading their control crystal. However, it is important to note that a player cannot control a familiar of a higher level than himself.

Since they were killed by the capture process, familiars are technically undead creatures kept alive solely by the power of their crystal, which means they cannot be killed again. This allows them to start each fight will full health and energy, even if they were defeated during the previous fight. However, familiars can still receive healing spells during combat.

Familiars are not controlled by the player; they follow him around on the battlefield, act the same as before their capture (but on the player's side!) and are still subject to all combat rules, with one exception: they can sometimes resist the power of the crystal and not act when their turn comes. A creature's resistance to a control crystal depends on their title. A familiar's resistance to its crystal is refered to as its action rate. It can be completely overcome using elemental fruits. Elemental fruits also improve/customise a familiar's aura.