Defeating The Metal Armor:

He will try to spin around to attack you. You must dodge it, and when he stops, use the spell that grabs things. You must grab each of his four shields. When the shields hit the ground they will turn into monsters. Once you kill all four, he gets swords. He will stop spinning. Wait before you grab his head with the spell, because he will hit his swords on the ground. After he does this, grab his head and yank it off to defeat him.