On a mystical island where only kaiju live, Mothra was circling around in one area. Anguirus came and roared, asking the giant moth what she was doing. She screeched in frustration at him, which meant that she wanted him to go away. The two daikaiju exchanged roars, chirps, screeches and cries. Anguirus gave one last, low grunt then walked away. The unexpecting ankylosaur was spotted by 1954 Godzilla and 2001 Godzilla, who just began to head toward civilization to DESTROY ALL HUMANS! The two Godzillas approached Anguirus, still unexpecting. Mothra was still angrily circling in one spot, but stopped when she heard the scream of Anguirus. She slowly floated to the ground, then approached the three kaiju as fast as she could. In the distance, 2004 Godzilla, who was an Earth defender, rose from the trees and roared forcefully,
stomping over to the battle. King Ghidorah (who died in "Anguirus vs. King Ghidorah") rose after coming back to life and flew, feeling the need to join as well. In "Anguirus vs. King Ghidorah", Fire Rodan died, but now came back to life. He flies and joins the beginning battle.
King Ghidorah zaps Mothra, Fire Rodan, and Anguirus with his anti-gravity beam while slapping 2004 Godzilla with his tails. Mothra, Fire Rodan, and 2004 Godzilla then shoot King Ghidorah with their main beams. Anguirus is attacked by 1954 Godzilla and 2001 Godzilla, but Mothra then pushes them out of the way with her triple prismatic beam. After much battling, the only kaiju that didn't retreat were Mothra, Anguirus (oddly), and King Ghidorah. King Ghidorah throws Anguirus out of the way, but he is still in the battle. Mothra fires her beam, but King Ghidorah shakes his heads then "laughs". He then zaps Mothra, picks her up with his heads, then throws her far. Anguirus sneaks up on him and hits him with his Sonic Screech. King Ghidorah looks back at Anguirus, then frowns and angrily shoots him with an anti-gravity beam. Anguirus is pushed back, but somehow withstands the attack. Mothra comes back, looking weak, and King Ghidorah eyes her after temporarily pushing away Anguirus. She hurries back to the place she was circling at first, then lays down. Anguirus prevents King Ghidorah from getting to her by keeping him in one place. The weakened Mothra uses the rest of her strength to create a large egg, then dies. Anguirus retreats from King Ghidorah, who has not won the battle yet. Mothra is reborn from the egg with a boy larva. The two larvae battle King Ghidorah, but end up cocooning themselves in silk and becoming adults. The boy larva turns out to be Mothra Leo, and becomes Rainbow Mothra Leo. Mothra knew she couldn't win by herself, but her son helped her finally kill King Ghidorah.