I have completed all the tasks and killed all the creatures in all the challenges. I've scoured each area METICULOUSLY and yes I have killed everything (including the 3 invisible stalkers and burned the bitchy fission slime with fire and its definitely dead) but I am still not teleported to the chessboard, as I am told I should be. What have I not done or did wrongly?
The only thing I could think that might pose a problem is that I killed the fission slime and air aspect outside their homes (they followed my character out into the corridor) and hence the game perhaps did not register its death?? Also, I did the challenges in this order: Ice, Earth, Air, Fire.