Do you mean the 3 triangular teleporters in the north east of the fire forest? There is a corner of the teleporter that points in the direction it will teleport you...
Once you have the teleporter stones... <span class='standouttext'>Spoiler : </span><span class='spoiler'> teleport onto the east island using the teleporter pad, drop a teleporter stone, then take the triangular teleporter back. Use the teleporter stone to get onto the east island, then take the triangular teleporter to the western island.</span> (highlight the text to read)
Did you select the summoning doll, select that skill as either the primary or secondary skill, and click to attack? IIRC if you have an instant elemental attack as a primary skill and the character is set to aggressive, they will attack on their own. I think people mentioned that a different spell as a primary skill you would have to tell it to attack to start, but then it would continue on its own. With a spell selected as a secondary attack, there was no automatic casting even in aggressive mode. It is something like that anyway (I have not played a mage).
The teleporter stone you saw is actually the second of the pair. As you entered the little mushroom forest, there was a chest partially surrounded by rocks. Open the chest...
