X-Drive

The Symphogear X-Drive (シンフォギアXD [エクスドライブ] Ekusu-Doraibu is the evolved true form of the Symphogear. It is used in Episode 13 of the original series and Episode 13 of Symphogear G.

Information
This form is concealed within the Symphogear relics under 3,001,655,722 locks, and can only be unlocked under a high level phonic gain. In the original series the Lydian School anthem composed with the singer's hopes and futures are capable of unleashing this miracle for Hibiki, Tsubasa and Chris, while in G it was created for them as well as Maria, Kirika and Shirabe using everyone on Earth singing together with Serena's song.

When the X-Drive is active, the Symphogear gains a predominantly white color scheme and enhanced design, universally including the addition of angelic wings formed of colored light. In this state all Symphogears, regardless of their normal abilities, are capable of unassisted flight both in atmosphere and in space as well as telepathy with each other. All of the user's normal attacks can still be utilized, but at such a drastically greater level of both power and scope that destroying an entire army of Noise is an easy task, and even standing up to a fully energized complete relic becomes possible. On top of this the X-Drive can be used to bolster the strength of another wielded relic such as Solomon's Cane or Durandal.

The X-Drive's particular form and strength is based off the current level of power the Symphogear has achieved before unlocking it, as Hibiki, Tsubasa and Chris all possessed radically different X-Drive forms when they unlocked them again in G.

Trivia

 * In episode 13 of season 2 the X-Drive mode was activated by Superb Song born from 7 billion people.