Here is my first New Magic Item, Elemental Essence.
Elemental Essence: This powerful powder enables a PC to summon an elemental to serve him. If tossed into the air, it creates an Air Elemental. If sprinkled over a flame, it creates a Fire Elemental. If poured into water, it creates a Water Elemental. If mixed into some soil it creates an Earth Elemental. These are of the weakest (8 HD) variety. They last for the length of a standard potion. Once the elemental is summoned, it will only serve faithfully if the summoner rolls at or under his level on a D6 (for a multi-class PC, his highest level). If the roll is failed, the elemental will go berserk, attacking friend and foe alike. Therefore, a PC of 6th level or higher will always control the elemental. If two doses of Essence are combined, it will create a 16 HD Elemental, but the “Control” roll will be on a d10 instead of d6. XP: 600.