They mentioned earlier that Lucas reaped his soul before he turned to A Grim. Crazy young fanboy lol
"If you kill her, she will come back again. We share an irreversible bond, Greed. I don't think you would like to be on my bad side this time," warned Lucas to the younger Grim who worshipped him with his eyes.
Love all of that series! Great plot and the stories are set up to keep you wanting more. I read them out of order starting with Young Master Damien’s Pet. So worth every penny!