At the Heaven's Thorn Mage Tower.
The Elemental Pool here was slightly larger than the one in Herrera's Mage Tower, although the layout and the function were still identical. The positions of the various runes on the controlling magic seal were basically the same as well, so after nearly a month of use, Link now knew every inch of this Elemental Pool like the back of his hand.
Because it was the same type of spell as the Flaming Hand, the Fist of Firomoz also had similar Mana consumptions pattern with the former spell. It consumed 100 points of Mana in spell structure construction and 15 points per second to maintain it in normal conditions, which meant that it would consume 900 Mana Points per minute. When in active battles though, it would consume as much as 30 points of Mana per second or even 50 points per second if the battle was especially fierce.