The Millenia Bloom is a plant that can found in the Large Magellanic Cloud. The name is derived from the fact that it only grows once every Millennia. They are pollinated by an intergalactic insect species. When fully grown and blossomed, the flower will start to sing its siren song, which is able to look in someone's very being, consuming everything that makes that individual unique and leaves them in a vegetable state. The plantlike and soulless thing that remains, can be reshaped and forcibly controlled by someone else.
The Supreme Intelligence tried using the flower powers to remove the consciousnesses and take control of Rick Jones and Captain Marvel. He would have used their mindless husks as his own personal weapons, in particular, he wanted to use Jones' powers to destroy Earth, by using the Destiny Force, which Jones had previously employed during the Kree-Skrull War. However, its powers were nullified by Jones, due to him firing anti-matter nuclear missiles into the sun, that created a massive sun flare, neutralizing all the machines, including the Supreme Intelligence, around them and in doing so seemingly stopping the effects of the flower.
Following Ms. Marvel's capture by Ronan the Accuser, who was mind-controlled by the Supreme Intelligence. He tried to use the Millennia Bloom, he had locked up in stasis, to perform the same ritual he tried to perform on Rick Jones. He wanted to exploit the flower, to separate Danvers' human and Kree part, and utilize the latter to create a new and improved Kree race. However, her mind and soul were whole and the procedure was unable to be completed.