Rosa's soul
A lot of Lightning Eagles had fallen. There was no doubt that they were great resources for the husband and his surprise for the eternal enemy up in heaven. The husband could become a cultivator and turn those into lightning resistance and other pleasant surprises for the lightning believers.
With Rosa's lightning sword by his side, Kyoya spent a rare time alone. No one was around him, even his son who was going around with Xiaoxiao to help others. It seemed like Xiaoxiao's gentle side to help others was slowly invading Kuro's heart and he would turn into a man who would gladly help others.
Of course, the husband's room reeked off with the blood and lightning eagles, as resources, formed a gore scene in the room. Luckily enough, most of the stuff was within the inventory and Kyoya just had to take it outside to properly use his powers.