She seeks her for some unknown purpose, that involves a giant black door deep in Elior Forest .
Pandora persuaded Regulus to accompany her to attack Elior Forest and succeeded. Also, Regulus sees Pandora as a higher ranked member of the Witch Cult, unusually referring her with "sama"
Unlike the rest of world, Echidna seems to at least be acquainted with Pandora, describing her to be the Witch of Vainglory to Emilia during her trial. However, she is dismissive of Pandora's power, claiming that it made her an expert at saving her own skin.