Avenging Auras Adversely Affect Antagonist Anomalies

When Batman first encountered the young amnesiac woman Violet Harper, he saw her manifest the ability project various colored auras around her body. Each of these manifested as a unique ability, which she used in her costumed career as the superheroine known as Halo.

However, this wasn't the first time he saw such auras projected from a human, granting a person mighty powers. In fact, Batman himself had similiar aura-based energies on one occasion, years earlier when confronting his old foe... Doctor Double-X. And then several months later, after encountering the alien entity known as Aquarius. However, each time there was a different manifestation of this process.

In order to defeat Doctor Double X, Batman used the same device which the doctor developed to created his aura-clone, Double X, and spawned Double Batman. This energy duplicate had superstrength, the power of flight and could emit electrical charges from its hands. Once victorious, this Bat-aura destroyed itself, which would later be replaced by another avenging ace. 

Later, while Batman and his allies in the Justice League traveled to Earth-Two to assist the Justice Society in defeating the aggressive alien Aquarius, a residual effect when returning to Earth-One led to the Leaguers inadvertently birthing negative aura-clones of themselves. These had powers similar to the originals, which the heroes quickly vanquished.

While the laws of physics in the Earth-One realm naturally included the ability to split one's aura from oneself with the proper mechanism, the physical laws of Earth-Two were the reverse, with such auras being absorbed within a person through devices such as Doctor Mid-Nite's cryotuber and Aquarius’ cosmic radiation. 

Years later, the counterpart of the Aurakle alien which Violet merged with to become Halo was able to create its own body, separate from that of Harper's Earth-Two counterpart Marcie Cooper. This being, Chroma, was a physically separate manifestation from Cooper... much as the Double X clones were to Doctor Double X and Batman. Unlike Chroma, Aurakle wasn’t capable of accomplishing this feat.

With his prior experience with related powers, Batman was able to successfully train Halo in harnessing her own aura-abilities.