Shadow: Levels 10, 11, 12 and 13.
Flame: Levels 10, 11, 12, 13 and 14 (B). And this is the explanation for this:
This is another bug in the IR version (only in this version) in which you can turn into the flame in all the temple levels.
How to do it: Gain enough potions ; turn into your shadow (or press Shift-S) ; press Shift-K to decrease your health till one potion ; press Shift-T to increase your health till the maximum (12 potions) ; and voila, you will turn into the flame ... enjoy the great scene ;).