Procel is one of the 72 demons of King Solomon in the Ars Goetia. He holds the rank of Duke in Hell and commands 48 legions. He is associated with water, being able to warm water without fire and cause there to be heard a sound like that of rushing water. It's probable he was associated with hot springs as well.
In Dawn of Sorrow, Procel appears as a female (or dons a feminine appearance) and lets out a female scream when killed.
Procel essentially looks like a female face that is made out of water. She also resembles another enemy, the Mud Demon. She appears in the water-filled portions of the Subterranean Hell.
When the player enters or stands near a body of water inhabited by a Procel, she will materialize on its surface and charge at them. Her attack is easily avoided by jumping out of the way or by sinking deeper into the water. However, sometimes she will also charge blue energy inside her mouth, which she will use to unleash a powerful blast upon the player, potentially dealing considerable damage. It is slow, however, so it is also easily avoided.