He could try to create low-cost special puppets, ones that don't need to consume as much life force as recreating a living being, which demands far more energy to reproduce a complete lifeform.
As for Life Imprints, such things can be generated in the Virtual World controlled by Lilith. The Virtual World creates new lifeforms, generates corresponding Life Imprints, and then Zheng Yichen brings them into the real world as tangible, physical beings.
But to recreate something on the level of the Fate-Defying Supreme Demon, it would cost him several lives' worth of blood at the very least. Even then, the recreated Fate-Defying Supreme Demon would have numerous issues. It wouldn't just go mad from lacking a soul—it would likely harbor lingering memories, increasing the chances of hostility towards him.
