Information - Role

Emeralda's role in the storyline of Xenogears is relatively minor to that of the other battle party members. She isn't the one who awakened Deus, she isn't half of Deus, she's not secretly a Solarian Guardian Angel, she's not secretly royalty of a fallen monarchy, she's not half a research experiment set that involves combining gears and humans, she's not a fluffy teddy bear who's annoying, she's not a gun-toting male healer (curse restockable ammo!), and she's not a mutant. And you could go through the entire game without even delving into her past, since it's an optional side quest.

Quite frankly, such a minor addition is sort of refreshing, and all the more alluring.

The main significant roles of Emeralda can be whittled down to two main points. One is quite practical, from a gameplay perspective; as Elly suffers from the Aerith-syndrome, Emeralda replaces her as the possessor of elemental-based offensive ether. The second point is from a storyline and plot bunnie role, and is quite ingenious, actually; Krelian needed to research her in order to manipulate nanomachines, and eventually be able to revive Deus.

It's also interesting, since Emeralda, in battle, can be considered a mix of Fei and Elly... technically, she is their offspring, so seeing a mix of competent ether usage as well as competent melee attack power is awesome for many situations.