Use "Megamorph" while you control this monster to deal strict damage while battling a strong monster.
Due to its effect, your opponent will need a monster with over 5600 ATK (without killing their own monster) to beat "Gaia Plate" in battle while it is in attack position, or over 2000 ATK while it is in defense position.
This card is perfect to get rid of a "Stardust Dragon/Assault Mode" in battle since its second effect it's a continuous one that can't be negated by that monster's effect.
You can use cards like "Solomon's Lawbook" to guarantee an extra turn with "Gaia Plate".
You can use "Burial from a Different Dimension" or "Miracle Dig" to return up to 3 Rock-Type monsters to your graveyard to keep "Gaia Plate the Earth Giant" on the field (Since it will banish a Rock-Type monster each turn)