The mutation resulted in Biollante's appearance changing to appear more like King Ghidorah's - as well as gaining the power of Ghidorah's gravity beams.
The manga is an alternative version of Godzilla vs. King Ghidorah from the Heisei Era of Godzilla's films (1984 - 1995).
InformationEditThe Futurians (a group of human time travelers from Earth's 23rd century) appear to humanity - explaining who they are and stating they have a plan to finally rid Japan of Godzilla. Gaining humanity's trust, the Futurians drop their facade - revealing that they are in fact Xiliens and that they plan to take over Earth using the alien dragon, King Ghidorah.
Summoning the three headed Dragon, King Ghidorah began to fly towards Earth - unaware that a new opponent was unexpectedly in the way. Biollante - a monster created by Dr. Shiragami by fusing the DNA of Godzilla, a rose and his deceased daughter Erika - had flew into space after a battle with Godzilla a while back and was residing inside space debris. As King Ghidorah approached - Biollante revealed itself. Either due to seeing King Ghidorah as a threat to be eliminated or possibly due to Erika's desire to protect the Earth (or both), Biollante attacked the three headed dragon.
King Ghidorah, however, was unfazed and entered battle with the Godzilla hybrid. During the battle, King Ghidorah blasted Biollante with its gravity beams. However, this had a truly unexpected effect - as the Gravity beams proceeded to augment Biollante instead of harming it. Biollante's form changed, with its appearance becoming more like King Ghidorah's as the hybrid grew three heads as well as gaining a pair of enormous wings.
It also displayed the ability to fire gravity beams of its own, as this new hybrid of Biollante resumed battle with the alien aggressor. However, even the 'enhancements' that Biollante had gained as a result were insufficient to deal with the three head dragon, as King Ghidorah succeeded in presumably killing Biollante. With its unexpected attacker dealt with, King Ghidorah continued towards Earth to carry out its mission.
The Xilien's plan would still fail, however, with their saucer been destroyed and the Xiliens themselves been forced to live incognito among humanity following their failure.
Godzilla Raids Again (1992) - Manga