Fire Ultima

Fire Ultima is the most powerful spell to be cast, second most powerful fire spell, fourth most powerful spell, and the second most powerful spell to be cast at RuneScape. It needs 13 Air runes, 17 Fire runes, 1 Blood runes and 2 Death runes to cast and Alphans' Quest to be finished. You also need to buy Supreme Magic Potion, which aids you to get 119 Magic (which the potion boosts by 21-20 points). Beware, you will get 500 damage when drunk, and adds 200 more damage when drinking the second dose, 250 at the third, and 350 at the last dose (1300 altogether). Although this spell is very expensive, this can spawn three surges of fire then followed by Immobilize. Its maximum damage is 1142.