Great Zeorymer
Do not use Zeorymer unless the game forces you to. Go with the Nadesico on stage 11 and let Zeorymer destroy Lanster of Wind. On stage 21 go with the Archangel and let Zeorymer destroy Briest of Fire and Gallowin of Water. On stage 29 let Zeorymer destroy Rose C\\\'est La Vie of Moon. On stage 32, let Zeorymer destroy Dinoderos of Earth, Burrstone of Mountain and Omzack of Lightning. Afterwards, Great Zeorymer will come. Destroy it with Zeorymer. You should get Great Zeorymer on stage 36. After this point, you may use Great Zeorymer whenever you want.