This is literally Satan.. though, due to being in the pokemon world, he took on the form as one.

He is very satanic, dark, and loves to feast on anger,fear, mistrust, and sorrow, witch he uses to gain power.

He is the owner of the forbidden move: Great horns of Death, in which he turns into a large devil typhlosion, and is able to highly, extremely injure the opponent, and the enemy also gets the 'fear' debuff, which increases it's fear to anything