Ultimate Cosmo

Ultimate Cosmo is a transformation used by Cosmo in Sonic X series.

History
She only took on this form in "A Fearless Friend", where Earthia appeared to her and told her only she could save the galaxy. Cosmo's amulet then shattered and she transformed, helping Super Sonic and Super Shadow defeat Final Nova, an enhanced form of Dark Oak. Eventually, she sacrificed herself and fuses with the Dark Oak planet, allowing Miles "Tails" Prower to fire the Sonic Power Cannon, destroying the planet and killing Dark Oak and Cosmo. In the Japanese version, Sonic and Shadow used Chaos Regeneration in order to keep her alive. However, it turned her into a seed no one can react with. In the dub, Chaos Regeneration is not used and Cosmo implies the seed is her child.