Kelvin discarded the corpses of the first two by dismembering them and feeding the pieces to incursion zombies. Then he carried the three boxes and returned to the black market in hopes that they would accept the slave and return his money. It was the only chance of getting back his 20 million dollars.
Along the way, the two of them didn't talk to each other. Their mood was heavy and dark, just like the night. In fact, the night was better off because of all the glowing crystals created by the incursion.
There was at least some light in the dark. But there was only anger, frustration, and indignation between them.
Kelvin was angry, but he wasn't angry at Wrath for what she did to him. It is, as she said, she had no responsibility to warn him that he might be wasting his time and 20 million dollars on a null.