Doc was not phased by the semi-failure of the attempt to kill the invisible creature. Now he was mad. Really mad. When Marianne offered help, Doc scowled at her. 

"A normal person would give us the help without payment. Go to hell!" he yelled angrily. 

With only seconds to come up with an attack, he suddenly got an idea. Maybe he could temporarily blind the beast. Yes, yes that might work. He raised his hands high above his head, shutting his eyes tightly. His hands began to glow. Either this would heal the beast, or blind it. The spell was usually used for healing, but if he concentrated hard enough, he might just be able to just summon the light of it. 

Without any more hesitation, his hands began to glow extremely bright, as a small ball formed inside of them.