Dark Messiah of Might and Magic Elements

The earliest part of the game to gain this Achievement is at the beginning of
Chapter 7: Fire In The Blood.

You will now learn the ability to turn in your form of the demoniac, by tapping once. Straight after you have tapped press to swing your tail.

But be careful, once you are in your demoniac form, your health slowly falls down. To stop this from happening, kill more enemies to gain more health.

You will find plenty of 10 enemies to kill. You should gain this Achievement quite early in the chapter.

Before you give me a negative vote, please explain yourself why you did it and I will be more than happy to improve my solution. Thank You.