The Magical antifire was a planned combination potion that would have been released alongside other combination potions in the second batch of Prifddinas. It would have been created using the Herblore skill, with a level of 92. It would combine the effects of the extreme magic and super antifire potions.
In order to make this potion, players would have had to buy the recipe from the Meilyr recipe shop, for 300,000 first. It would have been made by using an extreme magic (4) on a super antifire (4) with a crystal flask in the player's inventory.