Esmeralda is a very powerful Diwata. In fact, she was the most powerful Diwata ever to live in Encantadia, but this was centuries ago. Meno told the story of this Diwata to his nephew, Raquim. Every word that Esmeralda would let go from her mouth would come true. When Etherians knew of her power, they tried to steal her scepter and killed her during the process. She cursed the Etherians that someone in the same race as her will be the cause of Etheria's downfall. She died making the scepter disappear with her to afterlife and doesn't let her soul be at peace unless she finds the rightful Encantada to wield it. Her dying curse instilled fear in the Etherians and was the main reason why Etherians enslaved the Diwatas because they feared the fulfillment of the curse. The curse was eventually fulfilled by the birth of Cassiopea. Esmeralda later entrusted the scepter to Cassiopea.
During the Sang'gres' intervention with the past, when Danaya was looking for Amihan, Esmeralda's spirit enveloped in a yellow green aura and flies to Danaya who thought she is an enemy. She appears in front of her and Danaya fought and strangled her. Esmeralda introduces herself and Danaya recognizes her. She tells Danaya her soul was never at peace until she finds the rightful Encantada to entrust her scepter. She found Danaya worthy and her scepter appears in Danaya’s hands. Danaya recognized the scepter as her’s, the scepter of the Diwatas, Esmeralda asks her to give it to the one who would be the first Queen of the Diwatas before leaving to be finally at peace (which changes the story of the scepter's entrustment to Cassiopea).
In the 2016 requel series, Esmeralda was briefly mentioned by Cassiopea as the deceased daughter of the late queen Demetria and the mother of Princesses Mine-a and Amihan. But no one knew that she left children after her death, only Cassiopea did. She is the grandmother of the four elemental Sang'gres.