I am not gonna tell you which one I like best, becasue it really depends on the setting. Here is what my associations with each are to help you decide:
pic 1 (VD): fire magic, violent demonic forces, barely contained in steampunk machinery. A place with potential physical dangers, burning, explosions.
pic 2 (Elhoim): Ghostly magic, cold but strong, harnessed with some daring into an evil machinery. Still, more magic than technology. A place with dangers to the mind more than the body.
pic 3 (Ratatosk): A cold magical force, harnessed safely by technology. If you read the manual, nothing bad is going to happen. There is power here, but it is at your service, not somethiing with a will of its own.