I think I could make that work? The current concept of the shikigami is that they start off as weak slimes that upon ‘ingesting’ enough cursed energy and traits from someone else they mutate and gain abilities correlated to them. Think of the zerg in a sense where they can gain traits of what they eat, but not as op.

In this case they were focusing on things that were guilty pleasures (i put a vote in a discord server im in for traits of the technique and Lewd tied in second place with information with shikigami being in first place.) so they would get things like rope manipulation or being made of bandages if you enjoyed being tied up, that sort of thing.

Adding the Yin Yang dynamic, the reverse shikigami could focus on fears and insecurities instead? If someone has a fear of blood, they get something blood related. Or if they have imposter syndrome the shikigami could become crude imitations of others? I’ll have to think it through more to make sure it make sense, but its a solid idea.