Qualified

The Qualified (資格者) were special individuals chosen by the Blue to stay in the world during the Day of Ruin.

Information
The qualified possessed dreams strong enough to reconstruct the world with a fragment of Blue. To obtain it, they had to defeat Hades: Izanami, but their desired worlds were denied by the superior qualified, the wielder of Master Unit.

They could use Ars Magus even in the world without any Magic Element, and they could also detect other qualified. Their souls were being slowly absorbed into the Boundary, which made them weaker. Drives also make their possessors weaker.

Since Ragna the Bloodedge was not a qualified, and he was born without a Drive, his capacity for Magic Element allowed him to remove the qualifications of others by consuming their desires, making them forget about their dreams, with his Soul Eater. As all the characters lost their desires and qualifications, they turned into Magic Element, but the only way to stop the Day of Ruin was for someone to obtain the Blue.

Ragna obtained it, and used the Master Unit to create a new world from all the desires he consumed.

Trivia

 * The Qualified were localized as the "Entitled" in BlazBlue: Chronophantasma, and as the "Chosen" in BlazBlue: Centralfiction.