The principle of control led to the desire to control led to the desire to command led to the desire to rule.
The desire to rule led to the question of how to rule which led to the question of "what must one be to be a ruler."
Charisma. Fleeting, weak, useless.
Regulations, disgusting.
In this world, consider what type of existence was sufficient to rule.
Gods.
Error: A god already exists. The mind is non-god, therefore cannot rule over god. Solution: Become god, dispose of old god.
Goshintai had been used a second time after Erika had abandoned the conversation with that flame witch, and now the young girl sighed to herself, crossing her arms behind her head. Of course she had seen the great "Lord Death" in her myriad strolls within the city, or rather had perceived him with the Eye of Providence a few times and subsequently exiting the city before she was discovered. Know thine enemy, and whatnot.
Regardless, she needed to...test the waters, so to speak. See how the city would react to a sudden threat.
Or perhaps this was all just a rationalization to do something, and shove off her inane boredom.
Devil's Projection, the capability to recreate "anything" the user has seen. While seemingly an omnipotent ability, it has its weaknesses. The first is that it can't make something which currently "is." Say Erika sees a sword, she cannot use Devil's Projection to make that sword as it exists in that form. If she breaks the sword though, then she can create the sword in its original state, because the unbroken sword "no longer exists in that same form."
By this logic, even living beings can be made, providing that they "no longer exist in their current form." Let's say Erika spies a little boy, then the little boy dies. She could theoretically use Devil's Projection to create the little boy, as the image she recorded of "the living little boy" no longer exists in the world in that same form. This however moves into the second weakness of Devil's Projection: its cost. When used directly, it operates simply; the stronger the thing being brought into reality, the higher the energy needed. A sword requires little. A magic weapon requires more. A living being requires quite a lot, and the stronger the living being the more energy it would cost.
She could manage creating a handful of Kishin Eggs without much issue, but something like a witch of roughly equal power to her would drain her of almost all energy. This is why she couldn't do something like make an army by creating thousands of dead people with Devil's Projection, she'd run out of energy due to the natural cost of Devil's Projection.
All the same, with what energy she had left, she could manage this next bit, she'd just have to go rest in some corner of the world while she watched the events play out.
Devil's Projection was activated, and three Kishin Eggs Erika had previously seen, all of which were of course long-dead, appeared. Since they no longer existed in the form she was making them, it was wholly possible.
One bore sharp, bird-like talons, its face a white mask with multiple eye sockets running haphazardly over it. One had the appearance of a stitched-up monster, the flesh beneath the skin just bursting at the seams. The other was a completely black entity, like a human wearing an utterly black skin-tight suit. Each were the "possession" of Erika, utterly subject to her will.
"Go to the city, muck around a bit, kill some things, then get killed by some students."
Such are the orders given as the newly-crafted Kishin Eggs depart for Death City.