The guy's name is Gurdy (<- Pshyco weirdo!!! But funny...).

Finishing the level you just need to go into the right quick sand then go through the other part.

The "Treasure":
1. Cast thunder on the largest cactus.
2. Cast Gravity ont he tent.
3. Cast Fire on the mushroom rock.
4. Cast Blizzard on the rcks- Smallest to Largest.
5. Cast holy on the flower.

Then you'll get the 'Unknown' element for a particular miasma stream.