Why Is Your Soul-Travel System a Inner-World Template?

After narrowly losing a sword clash to a speeding truck, Narukami Yu suspects something went wrong with his transmigration. The people around him are one of a kind, including but not limited to his unexpectedly curvy tomboy best friend, a precocious dark-skinned gyaru in his class, a mature and alluring school nurse, and a haughty, cold disciplinary committee member... He thought this was just an ordinary hidden world, but the Soulslike System that came with him has him convinced there's something seriously wrong with this place! He watches what he says and keeps a low profile, afraid some old bastard is lurking somewhere, ready to ambush him. Then one day, a beautiful girl who looks like Higuchi Oka becomes his desk mate, and the Soulslike System, dormant until now, finally stirs: [New target detected] [Target: Witch of the King who defies the Sacred Tree] [Talk] [Hug] [Kiss] [Start a game] "?" Bro, how are these options for taking down a target anything like what I imagined? Why are you calling magical girls the Scarlet Goddess, the Strange-Changing Enchantress, and the Mother of Plagues? ...Wait, what do you mean by "an avatar of the unspeakable"?