If you use the dragon stone to teleport away from a tough fight, be careful about using the 'leave battle tower' option, as it will return you to the same place (not sure if opponents will be back at their default locations, though, if they moved to attack you).
For the dragon morph stone, you may just need to move closer to the edge of the trail, and away from any boulders, etc. If not, just jump off the mountain or swim a bit out from land.
If you attack the imps with a bow or spells from a distance, and take out one or two you should be able to retreat in order to heal, and have a little easier time for the next attack. Trying to get 4k experience from the imps on level 17, I had to do a fair bit of running away (jumping slightly diagonally left or right, trying to avoid magic attacks) until I got my creature using a ranger head (then I still had to run away a bit).
