The true antagonist and final boss of Kirby: Triple Deluxe. She is a giant, beauty-obsessed wasp queen who has been terrorizing the people of the sky well before the events of the main story. Said main story kicks off when the people have had enough of her tyranny and decide to summon a hero with the Dreamstalk.
Hearing about this rebellion, the twisted queen sends her trusted servant Taranza to capture this hero. When Taranza fails her by mistaking King Dedede as the hero (and thus incurring the wrath of Kirby), Sectonia supposedly offs her servant and takes matters into her own hands.
After a long, drawn-out battle (which included Sectonia fusing with the Dreamstalk), Kirby defeats her with his newly-discovered Hypernova ability.
Flavor text from her boss fights, as well as Miiverse posts from Kumazaki Shin'ya, reveal that she has not always been evil. In fact, she was rather benevolent to her people. It was thanks to constantly gazing in the Dimension Mirror (gifted to her by Taranza) that pushed her down the path of villainy. Whether or not Dark Meta Knight or Dark Mind (who is implied to be still alive in the form of King D-Mind) is responsible for this remains unknown.
She is also implied to not have always had the form of a wasp. DNA informaton (courtesy of the Haltmann Works Company) suggests that she acquired that form through magic and feeding off of countless hosts. When her clone is defeated in Kirby: Planet Robobot, she shows her base form like the Dark Matter clone did for itself in the prior fight, which looks like a feminine version of Taranza. This suggests that the two are of the same species and were even very close friends or lovers at some point.
