Yosuga is a Reason, a powerful inner philosophy that encompasses a set of natural laws, based on elitism and survival of the fittest, where only the chosen elite would possess the right to live. The useless and weak elements of society would be purged from the world, leaving only the powerful and strong. Power is acknowledged as being the only thing of true worth, and only the strongest of the strongest would have the right to rule. This Reason is most closely associated with the Chaos alignment of previous Shin Megami Tensei games.
Calling the previous world too cluttered and full of unnecessary things, she resolves to create a simple, primal world where the strong reign supreme and the weak are disposed of. Thus, she establishes the Reason of Yosuga.