"Sweetie, you can't be serious right now," Ziek said, holding Bing Shi by her wrists, stopping her from trying to climb him, "This is going to end badly, trust me."
"Keepsake Azumi Ray's (Bing Shi current body's) soul in my stead, please. I want to try another thing," Bing Shi pleaded, giving him the best puppy eyes, "The faster Tyrion learns to understand, the faster he will give up on his ex soul mate and move on to a new one."
She wanted to see Tyrion's reaction to Dai An existence, but it didn't mean she couldn't add more salt to the wounds.
Azumi Ray's soul was a cover to hide Bing Shi's soul, so if Ziek covered his with hers (Azumi's), Tyrion should automatically become obsessed with him, and Bing Shi could finally drill into his thick skull that a soul doesn't determine a person's worth.
She could have done that by becoming even more cruel and cold, but she wasn't a sadist who enjoyed torturing others.